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  • Electronic Resource  (85)
  • 2005-2009  (3)
  • 1990-1994  (82)
  • 12.39.Jh Nonrelativistic quark model
  • biodegradation
  • 1
    Electronic Resource
    Electronic Resource
    Isolation of Fenitrothion-degrading Strain Burkholderia sp. FDS-1 and Cloning of mpd Gene (2006)
    Springer
    Biodegradation 17 (2006), S. 275-283 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; Burkholderia ; fenitrothion ; mpd gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A short rod shaped, gram-negative bacterium strain Burkholderia sp. FDS-1 was isolated from the sludge of the wastewater treating system of an organophosphorus pesticides manufacturer. The isolate was capable of using fenitrothion as the sole carbon source for its growth. FDS-1 first hydrolyzed fenitrothion to 3-methyl-4-nitrophenol, which was further metabolized to nitrite and methylhydroquinone. The addition of other carbon source and omitting phosphorus source had little effect on the hydrolysis of fenitrothion. The gene encoding the organophosphorus hydrolytic enzyme was cloned and sequenced. The sequence was similar to mpd, a gene previously shown to encode a parathion-methyl-hydrolyzing enzyme in Plesiomonas sp. M6. The inoculation of strain FDS-1 (106 cells g−1) to soil treated with 100 mg fenitrothion emulsion kg−1 resulted in a higher degradation rate than in noninoculated soils regardless of the soil sterilized or nonsterilized. These results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10532-005-7130-2
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  • 2
    Electronic Resource
    Electronic Resource
    The Impact of Bioaugmentation on Metal Cyanide Degradation and Soil Bacteria Community Structure (2006)
    Springer
    Biodegradation 17 (2006), S. 207-217 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; DGGE ; K2Ni(CN)4 soil bacterial populations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Metal cyanides are significant contaminants of many soils found at the site of former industrial activity. In this study we isolated bacteria capable of degrading ferric ferrocyanide and K2Ni(CN)4. One of these bacteria a Rhodococcus spp. was subsequently used to bioaugment a minimal medium broth, spiked with K2Ni(CN)4, containing 1 g of either an uncontaminated topsoil or a former coke works site soil. Degradation of the K2Ni(CN)4 was observed in both soils, however, bioaugmentation did not significantly impact the rate or degree of K2Ni(CN)4 removal. Statistical analysis of denaturing gradient gel electrophoresis profiles showed that the topsoil bacterial community had a higher biodiversity, and its structure was not significantly affected by either K2Ni(CN)4 or bioaugmentation. In contrast, profiles from the coke works site indicated significant changes in the bacterial community in response to these additions. Moreover, in both soils although bioaugmentation did not affect rates of biodegradation the Rhodococcus spp. did become established in the communities in broths containing both top and coke works soil. We conclude that bacterial communities from contaminated soils with low biodiversity are much more readily perturbed through interventions such as contamination events or bioaugmentation treatments and discuss the implications of these findings for bioremediation studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s10532-005-4219-6
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  • 3
    Electronic Resource
    Electronic Resource
    P-wave charmonium decays into baryon and antibaryon pairs in quark pair creation model (2005)
    Springer
    The European physical journal 23 (2005), S. 129-133 
    Details
    ISSN: 1434-601X
    Keywords: 13.25.Gv Decays of J/ψ, ϒ, and other quarkonia ; 12.39.Jh Nonrelativistic quark model ; 14.20.Jn Hyperons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. A simple quark pair creation model is introduced to study exclusive decays of χ{c_J} into baryon-antibaryon pairs. With this simple model, some exclusive decay processes, for example, χ{c0} → B¯ (B = Λ,Σ0,Ξ-) are investigated and their decay widths are evaluated by inclusion of the properties of outgoing baryons, and the results show that the strengthened decay channels χ{c_J} → Λ¯(J = 0, 2) are easily understood by considering only the color singlet contribution of P-wave charmonium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1140/epja/i2004-10069-9
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  • 4
    Electronic Resource
    Electronic Resource
    Novel malonate-type copolymers containing vinyl alcohol blocks as biodegradable segments and their builder performance in detergent formulations (1994)
    Springer
    Journal of polymers and the environment 2 (1994), S. 89-97 
    Details
    ISSN: 1572-8900
    Keywords: Polycarboxylate ; methylene malonate copolymer ; biodegradation ; design ; poly(vinyl alcohol)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Poly[(disodium methylene malonate)-co-(vinyl alcohol)] [P(DSMM-VA)] and poly[(disodium ethoxymethylene malonate)-co-(vinyl alcohol)] [P(DSEMM-VA)] containing a poly(vinyl alcohol) (PVA) block as a biodegradable segment were prepared and their biodegradability and functionality were evaluated and compared with those of the corresponding fumarate and maleate copolymers. It was found that the 1,1-dicarboxylate-type copolymers, P(DSMM-VA) and P(DSEMM-VA), showed better biodegradability than the corresponding 1,2-dicarboxylate-type copolymers, P(DSF-VA) and P(DSM-VA). This improved biodegradability of P(DSMM-VA) and P(DSEMM-VA) is probably attributable to their more expanded polymer chain in aqueous solution, which will be more accessible to the degrading enzymes. The minimum chain length of the PVA-block, which acts as a biodegradable segment in the polymer chain, is estimated to be 2–3 and 3–4 monomer units for P(DSMM-VA) and P(DSEMM-VA), respectively. On the other hand, the minimum PVA block is about 5 and 7 monomer units for the fumarate and maleate copolymers, respectively. It was confirmed that P(DSMM-VA) showed excellent builder performance compared to the corresponding fumarate copolymer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02074777
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  • 5
    Electronic Resource
    Electronic Resource
    Biodegradability of blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with cellulose acetate esters in activated sludge (1994)
    Springer
    Journal of polymers and the environment 2 (1994), S. 49-57 
    Details
    ISSN: 1572-8900
    Keywords: Poly(3-hydroxyalkanoates) ; cellulose acetate esters ; biodegradation ; activated sludge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Blends of the bacterially produced polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with cellulose acetate esters (CAE) further substituted with propionyl or butyryl groups (degree of substitution: 2.60 propionyl and 0.36 acetyl or 2.59 butyryl and 0.36 acetyl, respectively) were exposed for 4 months to activated sludge to determine their biodegradability. Samples of such blends made by solution-mixing and solvent-casting had complex morphologies in which both individual components as well as a miscible blend phase were present. Additionally, the two opposite surfaces of solvent-cast films showed both physical and chemical differences. After 2 months, samples of pure PHBV had degraded by more than 98% (15 mg/cm2 of surface area), whereas a pure CAE sample had degraded less than 1% (〈0.2 mg/cm2). Samples containing 25% CAE lost less than 40% of their initial weights (6 mg/cm2) over the total 4-month period. Samples with 50% CAE lost up to 16% weight (2 mg/cm2), whereas those containing 75% CAE lost only slightly more weight than corresponding sterile control samples (1 mg/cm2). NMR results confirm that weight loss from samples containing 25% CAE resulted only from degradation of PHBV and that the surface of samples became enriched in CAE. Solvent-cast film samples containing equal amounts of PHBV and CAE degraded preferentially on the surface which formed at the polymer-air interface. Scanning electron microscopy and attenuated total reflectance infrared spectroscopy revealed this surface to have a rougher texture and a greater PHBV content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02073486
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  • 6
    Electronic Resource
    Electronic Resource
    Influence of metal complexation on the metabolism of citrate byKlebsiella oxytoca (1994)
    Springer
    BioMetals 7 (1994), S. 163-169 
    Details
    ISSN: 1572-8773
    Keywords: biodegradation ; Klebsiella oxytoca ; metal-citrate complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The uptake of 14C-labeled cadmium-, copper and zinc-citrate into cells of Klebsiella oxytoca was followed. The study was made in order to examine if the earlier reported disability of the bacterium to degrade these complexes was due to an inhibition in transport through the cell membrane. Citrate complexed to cadmium, copper or zinc was taken up at a similar rate to the free citric acid. However, the metal-citrate complexes were not metabolized as shown by the marked accumulation of 14C in the cells as compared with the 14C content in the cells incubated with free citric acid. This was confirmed by the results from trichloroacetic acid-precipitation showing that no 14C was incorporated into macromolecules when the citrate was complexed to the different metals. It is suggested that the inhibited degradation was due to effects on the interaction between enzyme (aconitase) and substrate in the conversion of citrate to iso-citrate. The role of complex configuration on the mineralization of metal-citrate is discussed and also tested in mineralization studies of other metal-citrate complexes (aluminum-, calcium-, cobalt-, manganese- and nickel-citrate).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140487
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  • 7
    Electronic Resource
    Electronic Resource
    Physiological properties and substrate specificity of a pentachlorophenol-degradingPseudomonas species (1994)
    Springer
    Biodegradation 5 (1994), S. 47-54 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; dechlorination ; pentachlorophenol ; Pseudomonas sp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A bacterial strain capable of utilizing pentachlorophenol (PCP) as sole source of carbon and energy for growth was isolated from enrichment cultures containing 100 mg/l PCP in a mineral salts medium inoculated with contaminated soil from a lumber treatment waste site. The isolate, designated strain SR3, was identified as a species ofPseudomonas by virtue of its physiological and biochemical characteristics. Mineralization of PCP byPseudomonas sp. strain SR3 was demonstrated by loss of detectable PCP from growth medium, stoichiometry of chloride release (5 equivalents of chloride per mole of PCP), and formation of biomass consistent with the concentration of PCP mineralized. PCP-induced cells of strain SR3 showed elevated rates of oxygen consumption in the presence of PCP, and with different chlorinated phenols, with complete degradation of 2,3,5,6-, 2,3,6-, 2,4,6-, 2,4-, and 2,6-chloro-substituted phenols. Concentrations of PCP up to 175 mg/liter supported growth of this organism, but maximal rates of PCP removal were observed at a PCP concentration of 100 mg/liter. Based on its degradative properties,Pseudomonas sp. strain SR3 appears to have utility in bioremediation of soil and water contaminated with PCP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695213
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  • 8
    Electronic Resource
    Electronic Resource
    Molecular analysis of pentachlorophenol degradation (1994)
    Springer
    Biodegradation 5 (1994), S. 277-288 
    Details
    ISSN: 1572-9729
    Keywords: Pentachlorophenol ; biodegradation ; dechlorination ; dehalogenation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A limited number of microorganisms have been described for their ability to partially degrade pentachlorophenol (PCP), or to completely mineralize it. Several years ago we chose one of these microorganisms,Flavobacterium sp. strain ATCC 39723, for use in a detailed molecular analysis of the catabolism of PCP. This strain was chosen because it had previously been studied in great detail for its growth characteristics in relation to degradation of PCP. In this paper we provide an overview of the degradation pathway of PCP to 2,6-dichloro-p-hydroquinone byFlavobacterium. The specific biochemical reactions and the genes encoding the enzymes are reviewed. The successful transformation and site specific mutagenesis ofFlavobacterium, as well as the discovery of two newpcp alleles is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696465
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  • 9
    Electronic Resource
    Electronic Resource
    Reductive dehalogenation as a respiratory process (1994)
    Springer
    Antonie van Leeuwenhoek 66 (1994), S. 239-246 
    Details
    ISSN: 1572-9699
    Keywords: chlorinated compounds ; dechlorination ; bacteria ; anaerobic respiration ; co-metabolism ; biodegradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Anaerobic bacteria can reductively dehalogenate aliphatic and aromatic halogenated compounds in a respiratory process. Only a few of these bacteria have been isolated in pure cultures. However, long acclimation periods, substrate specificity, high dehalogenation rates, and the possibility to enrich for the dehalogenation activity by subcultivation in media containing an electron donor indicate that many of the reductive dehalogenations in the environment are catalyzed by specific bacteria. Molecular hydrogen or formate appear to be good electron donors for the enrichment of such organisms. Furthermore, systems have to be employed which supply the cultures with the halogenated compounds beyond their toxicity level. All bacteria that are presently available in pure culture and grow with a halogenated compound as electron acceptor are members of new genera. Based on experimental results with the membrane-impermeable electron mediator methyl viologen, a model of the respiration system ofDehalobacter restrictus, a tetrachloroethene-dechlorinating bacterium, is presented. Further studies of the biochemistry and energetics of respiratory-dehalogenating strains will help to understand the mechanisms involved and perhaps reveal the evolutionary origin of the dehalogenating enzyme systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00871642
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  • 10
    Electronic Resource
    Electronic Resource
    Genetics and biochemistry of 1,2-dichloroethane degradation (1994)
    Springer
    Biodegradation 5 (1994), S. 249-257 
    Details
    ISSN: 1572-9729
    Keywords: chlorinated hydrocarbons ; biodegradation ; 1,2-dichloroethane ; alkanes ; Xanthobacter ; dehalogenase ; adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Dichloroethane (1,2-DCE) is a synthetic compound that is not known to be formed naturally. Nevertheless, several pure microbial cultures are able to use it as a sole carbon source for growth. Degradation of 1,2-DCE proceeds via 2-chloroethanol, chloroacetaldehyde and chloroacetate to glycolate. The genes encoding the enzymes responsible for the conversion of 1,2-DCE to glycolic acid have been isolated. The haloalkane dehalogenase and an aldehyde dehydrogenase are plasmid encoded. Two other enzymes, the alcohol dehydrogenase and the haloacid dehalogenase, are chromosomally encoded. Sequence analysis indicates that the haloacid dehalogenase belongs to the L-specific 2-chloroproprionic acid dehalogenases. From the three-dimensional structure and sequence similarities, the haloalkane dehalogenase appears to be a member of the α/β hydrolase fold hydrolytic enzymes, of which several are involved in the degradation of aromatic and aliphatic xenobiotic compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696463
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  • 11
    Electronic Resource
    Electronic Resource
    Biotransformation of quinoline and methylquinolines in anoxic freshwater sediment (1994)
    Springer
    Biodegradation 5 (1994), S. 113-120 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; quinoline ; methylquinolines ; anaerobic biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Quinoline (Q) and some isomers of methylquinoline (MQ) were transformed to hydroxylated products in freshwater sediment slurries incubated under methanogenic conditions at 25 °C. Methylquinoline transformation was not affected by a methyl group on the C-3 or C-4 carbon atom of the pyridine ring; 2-MQ, however, was not transformed. All isomers of dimethylquinoline (DMQ) tested (2,4-, 2,6-, 2,7-, and 2,8-DMQ) with a methyl group at the number 2 carbon also persisted in sediments after anaerobic incubation for one year at 25 °C. In most experiments, quinoline initially was transformed to 2-hydroxyquinoline (2-OH-Q), which was further metabolized to unidentified products. A second product, 4-CH3-2-OH-Q, was detected in some experiments. This product accumulated and was not further transformed. 6-, 7-, and 8-Methylquinoline (6-, 7-, 8-MQ) were hydroxylated to form the respective 2-OH-MQ products. These hydroxylated products accumulated and were not further transformed. Hydroxylation of Q and 6-, 7- and 8-MQ at the 2-carbon position was confirmed by GC/FTIR and GC/MS analyses. The transformations of Q and MQs were pH dependent with an optimal pH of 7–8. The results of this study suggest that two pathways may exist for the anaerobic transformation of quinoline; one pathway leads to the formation of a hydroxylated intermediate and the other to a methylated and hydroxylated intermediate. In addition, our results suggest that a methyl substituent on the number 2 carbon inhibits the anaerobic transformation of quinoline derivatives.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00700636
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  • 12
    Electronic Resource
    Electronic Resource
    Catabolic transposons (1994)
    Springer
    Biodegradation 5 (1994), S. 323-342 
    Details
    ISSN: 1572-9729
    Keywords: mobile DNA ; insertion sequence ; transposon ; catabolic pathways ; biodegradation ; toluene ; chlorobiphenyl ; chlorobenzoate ; oxygenase ; dehalogenase ; plasmid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The structure and function of transposable elements that code for catabolic pathways involved in the biodegradation of organic compounds are reviewed. Seven of these catabolic transposons have structural features that place them in the Class I (composite) or Class II (Tn3-family) bacterial elements. One is a conjugative transposon. Another three have been found to have properties of transposable elements but have not been characterized sufficiently to assign to a known class. Structural features of the toluene (Tn4651/Tn4653) and naphthalene (Tn4655) elements that illustrate the enormous potential for acquisition, deletion and rearrangement of DNA within catabolic transposons are discussed. The recently characterized chlorobenzoate (Tn5271) and chlorobenzene (Tn5280) catabolic transposons encode different aromatic ring dioxygenases, however they both illustrate the constraints that must be overcome when recipients of catabolic transposons assemble and regulate complete metabolic pathways for environmental pollutants. The structures of the chlorobenzoate catabolic transposon Tn5271 and the related haloacetate dehalogenase catabolic element of plasmid pUO1 are compared and a hypothesis for their formation is discussed. The structures and activities of catabolic transposons of unknown class coding for the catabolism of halogenated alkanoic acids (DEH) and chlorobiphenyl (Tn4371) are also reviewed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696468
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  • 13
    Electronic Resource
    Electronic Resource
    Estimates of Gibbs free energies of formation of chlorinated aliphatic compounds (1994)
    Springer
    Biodegradation 5 (1994), S. 21-28 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; chlorinated compounds ; Gibbs free energy of formation ; group contribution method ; xenobiotic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Gibbs free energy of formation of chlorinated aliphatic compounds was estimated with Mavrovouniotis' group contribution method. The group contribution of chlorine was estimated from the scarce data available on chlorinated aliphatics in the literature, and found to vary somewhat according to the position of chlorine in the molecule. The resulting estimates of the Gibbs free energy of formation of chlorinated aliphatic compounds indicate that both reductive dechlorination and aerobic mineralization of these compounds can yield sufficient energy to sustain microbial growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695210
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  • 14
    Electronic Resource
    Electronic Resource
    Accelerated biodegradation of atrazine by a microbial consortium is possible in culture and soil (1994)
    Springer
    Biodegradation 5 (1994), S. 29-35 
    Details
    ISSN: 1572-9729
    Keywords: attrazine ; biodegradation ; hydroxyatrazine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A mixed enrichment culture of microorganisms capable of accelerated mineralization of atrazine was isolated from soil treated with successive applications of the herbicide. Liquid cultures of this consortium, in the presence of simple carbon sources, mineralized 96% of the applied atrazine (0.56 mM) within 7 days. Atrazine mineralization in culture is initiated with the formation of the metabolite hydroxyatrazine. In soil treated with atrazine at a concentration of 0.14 mM (concentration is based on total soil mass), and then inoculated with the microbial consortium, the parent compound was completely transformed in 25 days. After 30 days of incubation, 60% of the applied atrazine was accounted for as14CO2. As was found with the liquid cultures, hydroxyatrazine was the major metabolite. After 145 days, soil extractable hydroxyatrazine declined to zero and 86% of the applied atrazine was accounted for as14CO2. No metabolites, other than hydroxyatrazine, were recovered from either the liquid culture or soil inoculated with the consortium. The use of the mixed microbial culture enhanced mineralization more than 20 fold as compared to uninoculated soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695211
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  • 15
    Electronic Resource
    Electronic Resource
    Degradation of oil sludge by landfarming — a case-study at the Ghent harbour (1994)
    Springer
    Biodegradation 5 (1994), S. 37-46 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; landfarming ; mutagenicity ; oil ; plant growth ; toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Large-scale landfarming experiments have been performed on a loamy sand soil. An amount of 1,350 m3/ha oil sludge together with nutrients (N,P,K) and a bacterial inoculum were applied at two different times over a five-year period. At both test periods, biodegradation of the hydrocarbons (HC) was best fitted with first order reaction kinetics with degradation rates ranging from about 4 g HC/kg dry soil per year to about 15 g HC/kg dry soil per year. Toxicity tests on the aqueous soil extracts as well as plant growth and worm tests on the landfarm soil showed no striking negative effects of residual hydrocarbons. Migration of oil, nitrate and phosphate to the groundwater was minimal. In view of the diversity of solvents recommended in the literature, twenty extractants were tested for their capacity to remove HC from the loamy sand soil. Chlorinated solvents, such as dichloromethane and chloroform, were the most effective. Yet, in view of its effectiveness and low toxicity, acetone appears a suitable solvent for the extraction of soils and sediments polluted with hydrocarbons. This case-study revealed that oil sludge can effectively be treated by landfarming, if appropriate technical measures are taken and a sufficient time (minimum 15 years) for bioremediation is provided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695212
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  • 16
    Electronic Resource
    Electronic Resource
    Enhanced biodegradation of phenanthrene in a biphasic culture system (1994)
    Springer
    Biodegradation 5 (1994), S. 93-103 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; PAH ; phenanthrene ; Pseudomonas aeruginosa ; bioavailability ; 2,2,4,4,6,8,8-heptamethylnonane ; surfactants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Degradation of phenanthrene byPseudomonas aeruginosa AK1 was examined in (i) an aqueous mineral salts medium to which phenanthrene particles of varying size (i.e. diameter) were added, and (ii) an aqueous/organic biphasic culture system consisting of mineral salts medium supplemented with 2,2,4,4,6,8,8-heptamethylnonane (HMN) as the phenanthrene-carrying organic phase. In both systems, the rate of phenanthrene biodegradation could be significantly enhanced by manipulations leading to improved phenanthrene mass transfer into the aqueous phase. With crystalline phenanthrene, the rate of biodegradation was found to be directly correlated to the particle surface area, whereas in the biphasic system the rate of biodegradation of the dissolved phenanthrene was mainly governed by the HMN/water interface area. In the latter system, exponential growth with a doubling time t d of 6–8 hours has been achieved under conditions of intensive agitation of the medium indicating that phenanthrene degradation by strain AK1 is limited mainly by physicochemical parameters. Addition of selected surfactants to the culture medium was found to accelerate phenanthrene degradation by strain AK1 only under conditions of low agitation (in the presence of HMN) and after pretreatment of phenanthrene crystals by ultrasonication (in the absence of HMN). Evidence is presented that the stimulating effect of the surfactants was primarily due to improved dispersion of phenanthrene particle agglomerates (in the aqueous mineral salts medium supplemented with phenanthrene crystals) or of the phenanthrene-carrying lipophilic solvent drops (in the aqueous/organic biphasic culture system) whereas the solubilizing activity towards phenanthrene was neglectible. Under conditions of intensive mixing of the culture medium (i.e. if a high particle surface area or HMN/water interface area, respectively, is provided), the addition of surfactants did not enhance phenanthrene biodegradation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00700634
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  • 17
    Electronic Resource
    Electronic Resource
    Genetic construction of PCB degraders (1994)
    Springer
    Biodegradation 5 (1994), S. 359-377 
    Details
    ISSN: 1572-9729
    Keywords: Aerobic bacteria ; biodegradation ; genetic manipulations ; polychlorinated biphenyls ; recombinant strains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Genetic construction of recombinant strains with expanded degradative abilities may be useful for bioremedation of recalcitrant compounds, such as polychlorinated biphenyls (PCBs). Some degradative genes have been found either on conjugative plasmids or on transposons, which would facilitate their genetic transfer. The catabolic pathway for the total degradation of PCBs is encoded by two different sets of genes that are not normally found in the same organism. ThebphABCD genes normally reside on the chromosome and encode for the four enzymes involved in the production of benzoate and chlorobenzoates from the respective catabolism of biphenyl and chlorobiphenyls. The genes encoding for chlorobenzoate catabolism have been found on both plasmids and the chromosome, often in association with transposable elements. Ring fission of chlorobiphenyls and chlorobenzoates involves themeta-fission pathway (3-phenylcatechol 2,3-dioxygenase) and theortho-fission pathway (chlorocatechol 1,2-dioxygenase), respectively. As the catecholic intermediates of both pathways are frequently inhibitory to each other, incompatibilities result. Presently, all hybrid strains constructed by in vivo matings metabolize simple chlorobiphenyls through complementary pathways by comprising thebph, benzoate, and chlorocatechol genes of parental strains. No strains have yet been verified which are able to utilize PCBs having at least one chlorine on each ring as growth substrates. The possible incompatibilities of hybrid pathways are evaluated with respect to product toxicity, and the efficiency of both in vivo and in vitro genetic methods for the construction of recombinant strains able to degrade PCBs is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696470
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  • 18
    Electronic Resource
    Electronic Resource
    Preparation of poly(phosphate ester)s having bisphenol moieties as mesogenic units in the main chain (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2119-2126 
    Details
    ISSN: 0887-624X
    Keywords: poly(phosphate ester)s ; liquid crystalline polymer ; smectic phase ; thermal stability ; biodegradation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(phosphate ester)s, PPE 1a-d, were synthesized from polycondensation of methyl phosphorodichloridate (MPDC) with various bisphenols such as 4,4′-biphenol 1a, 4,4′-dihydroxyphenylether 1b, bis(4-hydroxyphenyl)methane 1c, and 3,3′-dimethyl-4,4′-dihy-droxybiphenyl 1d. PPE 2a-d with hexamethylene spacers were also obtained from poly-condensation of MPDC with 4,4′-bis(6-hydroxyhexyloxy)biphenyl 2a, 4,4′-di(6-hydroxyhexyloxy)phenyl ether 2b, bis[4-(6-hydroxyhexyloxy)phenyl]methane 2c, and 3,3′-dimethyl 4,4′-di(6-hydroxyhexyloxy)biphenyl 2d. The degree of crystallinity of PPE 1a-1d without hexamethylene spacer was 3.3-17.6%, whereas PPE 2a and PPE 2b which exhibit mesomorphic behavior were 20.1 and 18.6%, respectively. PPE 2a and PPE 2b show the mesophase at 139.6-195.5°C and 42.4-66.3°C, respectively. PPE 2c and PPE 2d were obtained as rubbery. From pyrolysis of PPE in air the temperature corresponding to 5% weight loss was found to be 322-408°C and 284-291°C for PPE 1 and PPE 2, respectively. It was also found that PPE 2a was enzymatically degraded by phospholipase C. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321114
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  • 19
    Electronic Resource
    Electronic Resource
    Cyclodextrins as Mucosal Absorption Promoters of Insulin. II. Effects of β-Cyclodextrin Derivatives on α-Chymotryptic Degradation and Enteral Absorption of Insulin in Rats (1994)
    Springer
    Pharmaceutical research 11 (1994), S. 1174-1179 
    Details
    ISSN: 1573-904X
    Keywords: biodegradation ; stability ; α-chymotrypsin ; cyclodextrins ; enteral absorption ; histology ; insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The relative effectiveness of two β-cyclodextrin derivatives, i.e., dimethyl-β-cyclodextrin (DMβCD) and hydroxypropyl-β-cyclodextrin (HPβCD), in enhancing enteral absorption of insulin was evaluated in the lower jejunal/upper ileal segments of the rat by means of an in situ closed loop method. The incorporation of 10% (w/v) DMβCD to a 0.5 mg/ml porcine-zinc insulin solution dramatically increased insulin bioavailability from a negligible value (~0.06%) to 5.63%, when administered enterally at a dose of 20 U/kg. However, addition of 10% (w/v) HPβCD did not improve enteral insulin uptake significantly with a bioavailability of only 0.07%. Similarly, the pharmacodynamic relative efficacy values obtained after the enteral administration of 20 U/kg insulin, 20 U/kg insulin with 10% HPβCD, and 20 U/kg insulin with 10% DMβCD were 0.24%, 0.26%, and 1.75%, respectively. Biodegradation studies of 0.5 mg/ml insulin hexamers by 0.5 µM α-chymotrypsin revealed no inhibitory effect on the enzymatic activity by the two cyclodextrins. On the contrary, the apparent first-order rate constant increased significantly in the presence of 10% DMβCD, suggesting insulin oligomer dissociation by DMβCD. Histopathological examination of the rat intestine was performed to detect tissue damage following enteral administration of the β-cyclodextrin derivatives. Light microscopic inspection indicated no observable tissue damage, thereby arguing direct membrane fluidization as the primary mechanism for enhanced insulin uptake. This study indicates the feasibility of using cyclodextrins as mucosal absorption promoters of proteins and peptide drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018997101542
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  • 20
    Electronic Resource
    Electronic Resource
    Preparation and Characterization of Novel Poly(methylidene Malonate 2.1.2.)-Made Nanoparticles (1994)
    Springer
    Pharmaceutical research 11 (1994), S. 1270-1277 
    Details
    ISSN: 1573-904X
    Keywords: drug targeting ; polymeric drug carrier ; nanoparticle ; polymerization ; biodegradation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Poly(methylidene malonate 2.1.2.) (PMM 2.1.2.) nanoparticles were prepared in phosphate buffer through emulsion polymerization of monomeric units; the kinetics of the reaction was monitored by spectrophotometry at 400 nm. Average nanoparticle sizes, molecular weights, and biodegradability of this potential drug carrier were determined under various conditions. As previously demonstrated for other similar monomers, i.e. IHCA or IBCA, pH influenced the physico-chemical characteristics of the nanoparticles obtained. Ethanol release from the ester-bearing side chains indicated that the polymers were susceptible to hydrolysis when incubated in basic pH or in rat plasma. A secondary degradation pathway, yielding formaldehyde through a reverse Knoevenagel’s reaction, was minimal. Cytotoxicity studies of this new vector, in vitro, against L929 fibroblast cells demonstrated that PMM 2.1.2. nanoparticles were better tolerated than other poly(alkylcyanoacrylate) (PACA) carriers. Pharmacokinetic studies were also carried out to observe the fate of 14C-labelled PMM 2.1.2. nanoparticles after intravenous administration to rats. Forty eight hour post-injection, more than 80% of the radioactivity was recovered in urine and faeces. The body distribution of the polymer was estimated by measuring the radioactivity associated with liver, spleen, lung and kidneys. Five minutes after injection, a maximum of 24 ± 2% of the total radioactivity was detected in the liver and less than 0.4% in the spleen. The liver-associated radioactivity decreased according to a biphasic profile and less than 8% of the total radioactivity remained after 6 days.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018986226557
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  • 21
    Electronic Resource
    Electronic Resource
    Stimulation of environmentally controlled mushroom composting by polysaccharidases (1994)
    Springer
    World journal of microbiology and biotechnology 10 (1994), S. 313-319 
    Details
    ISSN: 1573-0972
    Keywords: Agaricus bisporus ; biodegradation ; cellulases ; compost ; lignocellulosics ; xylanases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Polysaccharidases adsorbed on commercial amylodextrins were added to environmentally controlled composts of straw plus poultry manure. After 5 days of composting at 48°C, microbial enzyme activities and numbers of bacteria were higher in the treated compost than in the control. During the next phase at 80°C, between days 5 and 6, more C and N were solubilized in the treated compost. After introducing a microbial inoculum on day 6, and maintaining the substrate at 48°C, colonization by bacteria was faster in the treated compost and consequently, more fibre was degraded. Differences between composts in yields of Agaricus bisporus after 5 weeks of cropping were not significant (P=0.05).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414871
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  • 22
    Electronic Resource
    Electronic Resource
    Metabolic engineering of Pseudomonas putida for the simultaneous biodegradation of benzene, toluene, and p-xylene mixture (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 43 (1994), S. 1146-1152 
    Details
    ISSN: 0006-3592
    Keywords: biodegradation ; benzene ; toluene ; p-xylene ; hybrid strain ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For the complete biodegradation of a mixture of benzene, toluene, and p―xylene (BTX), a critical metabolic step that can connect two existing metabolic pathways of aromatic compounds (the tod and the tol pathways) was determined. Toluate―cis-glycol dehydrogenase in the tol pathway was found to attack benzene―cis―glycol, toluene―cis―glycol, and p―xylene―cis―glycol, which are metabolic intermediates of the tod pathway. Based on this observation, a hybrid strain, Pseudomonase putida TB101, was constructed by introduction of the TOL plasmid pWW0 into P. putida F39/D, a derivative of P. putida F1, which is unable to transform cis―glycol compounds to corresponding catechols. The metabolic flux of BTX into the tod pathway was redirected to the tol pathway at the level of cis―glycol compounds by the action of toluate―cis―glycol dehydrogenase in P. putida TB101, resulting in the simultaneous mineralization of BTX mixture without accumulation of any metabolic intermediates. The profile of specific degradation rates showed a similar pattern as that of the specific growth rate of the microorganism, and the maximum specific degradation rates of benzene, toluene, and p-xylene were determined to be about 0.27, 0.86, and 2.89 mg/mg biomass/h, respectively. P. putida TB101 is the first reported microorganism that mineralizes BTX mixture simultaneously. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260431120
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  • 23
    Electronic Resource
    Electronic Resource
    Anaerobic acidogenesis of primary sludge: The role of solids retention time (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 7-13 
    Details
    ISSN: 0006-3592
    Keywords: anaerobic digestion ; acid phase ; volatile fatty acids ; biodegradation ; solids retention time ; sludge, primary ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This research investigates the effect of solids retention time (SRT) on the acid-phase anaerobic digestion of primary sludge. A series of experiments were conducted using two continuous-flow 3-L units with the following configuration: a completely mixed reactor (CMR) with clarifier and solids recycle and an upflow anaerobic sludge blanket (UASB) reactor. Results show that C2 to C5 volatile fatty acids (VFA) were the predominant compounds formed. At a constant hydraulic retention time (HRT) of 12 h, variation in SRT from 10 to 20 days resulted in a slight increase in VFA production in both systems, but at a shorter SRT (5 days) a drastic drop in acid production was observed. In addition, the percent distribution of VFA was to some extent affected by the change in SRT. On the other hand, organic matter degradation [measured by the chemical oxygen demand (COD) specific solubilization rate or the percent volatile suspended solids (VSS) reduction] appeared to be independent of SRT, at least in the range investigated. The percent soluble COD in the form of VFA, however, increased steadily with increasing SRT, approaching the 90% level at 20 days. The remaining soluble COD in the effluent from these systems may be mainly attributed to metabolic intermediates and unused soluble substrate. © 1994 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440103
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  • 24
    Electronic Resource
    Electronic Resource
    Production of lignin peroxidase by Phanerochaete chrysosporium immobilized on porous poly(styrene-divinylbenzene) carrier and its application to the degrading of 2-chlorophenol (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 79-86 
    Details
    ISSN: 0006-3592
    Keywords: lignin peroxidase ; Phanerochaete chrysosporium ; white-rot-fungus ; polymers ; immobilization ; 2-chilorophenol ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Porous poly(styrene-divinylbenzene) carriers, for the immobilization of white rot fungus Phanerochaete chrysosporium have been prepared by the concentrated emulsion polymerization method. The concentrated emulsion consists of a mixture of styrene and divinylbenzene containing a suitable surfactant and an initiator as the continuous phase, and water as the dispersed phase. The polymerization of the monomers of the continuous phase generated the polymer carrier with a porcus structure. The white rot fungus Phanerochaete chrysosporium has been immobilized on porous poly(styrene-divinylbenzene) carriers and used for the batch production and the repeated batch production of lignin peroxidase in shake cultures based on a carbon-limited medium containing veratryl alcohol. The best results were achieved when a spore inoculum was used for immobilization instead of 1-day-old mycelial pellets, for both the batch production and the repeated batch production. The porous poly(styrene-divinylbenzene) immobilized Phanerochaete chrysosporium and freely suspended mycelial pellets were used as biocatalysts for the degradation of 2-chilorophenol in a 2-L bioreactor. The porous poly(styrene-divinylbenzene) particle (diameter ≅ 0.2 cm) immobilized spores exhibited a much higher activity in the degradation of 2-chlorophenol than the freely suspended mycelial pellets. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440112
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  • 25
    Electronic Resource
    Electronic Resource
    Characterization of compost biofiltration system degrading dichloromethane (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 44 (1994), S. 1048-1054 
    Details
    ISSN: 0006-3592
    Keywords: biofiltration ; dichloromethane ; methylene chloride ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of acclimatization of microbial populations, compound concentration, and media pH on the biodegradation of low concentration dichloromethane emissions in biofiltration systems was evaluated. Greater than 98% removal efficiency was achieved for dichloromethane at superficial velocities from 1 to 1.5 m3/m3. min (reactor residence times of 1 and 0.7 min, respectively) and inlet concentrations of 3 and 50 ppm Although acclimatization of microbial populations to toluene occurred within 2 weeks of operation start-up, initial dichloromethane acclimatization took place over a period of 10 weeks. This period was shortened to 10 days when a laboratory grown consortium of dichloromethane degrading organism, isolated from a previously acclimatized column, was introduced into fresh biofilter media. The mixed culture consisted to 12 members, which together were able to degrade dichloromethane at concentrations up to 500 mg/L. Only one member of the consortium was able to degrade dichloromethane were sustained for more than 4 months in a biofilter column receiving an inlet gas stream with 3 ppmv of dichloromethane acidification of the column and resulting decline in performance occurred when a 50-ppmv inlet concentration was used. A biofilm model incorporating first order biodegradation kinetics provided a good fit to observed concentration profiles, and may prove to be a useful tool for designing biofiltration systems for low concentration VOC emissions. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260440905
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  • 26
    Electronic Resource
    Electronic Resource
    Extractive membrane bioreactors: A new process technology for detoxifying chemical industry wastewatersThis paper was the runner-up for the 1993 SCI Process Engineering Group Richardson Award Lecture Prize. (1994)
    Chichester : Wiley-Blackwell
    Journal of Chemical Technology AND Biotechnology 60 (1994), S. 117-124 
    Details
    ISSN: 0268-2575
    Keywords: extractive membrane bioreactor ; detoxification ; chemical industry wastewaters ; biodegradation ; point source treatment ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes an extractive membrane bioreactor developed to extract and biodegrade toxic organic pollutants present in chemical industry wastewaters. The technology is applicable to wastewaters emanating in organic synthesis operations which are not treatable by conventional ‘direct’ biological treatment due to extremes of pH, high salt contents, or otherwise hostile organic compositions, and also to wastewaters that contain volatile organic compounds. A laboratory scale prototype demonstrating the technology has been operated continuously over periods of several months, using industrially produced wastewaters. No pre-conditioning or dilution of the wastewaters is necessary prior to treatment, which removes and destroys over 99% of the toxic organics present.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jctb.280600202
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  • 27
    Electronic Resource
    Electronic Resource
    Influence of pH on the acid-phase anaerobic digestion of primary sludge (1994)
    Chichester : Wiley-Blackwell
    Journal of Chemical Technology AND Biotechnology 60 (1994), S. 89-96 
    Details
    ISSN: 0268-2575
    Keywords: anaerobic digestion ; acid-phase ; pH ; volatile fatty acids ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: This study explored the effect of pH on the acid-phase anaerobic digestion of primary sludge. Controlled and uncontrolled pH experiments were conducted using two bench-scale, continuous-flow reactors having different configurations: a completely mixed reactor (CMR) with clarifier and solids recycling, and an upflow anaerobic sludge blanket (UASB) unit. Results indicate that the specific rates of VFA production and COD solubilization, in either system, were not affected by the variation in pH between 4·3 and 5·2, but at higher pH values (5·9-6·2) a significant decline (by 25-30%) in both parameters was observed. Analysis of the degradation behavior of the three important organic classes (carbohydrates, proteins, and lipids) revealed that each class followed an individual trend with respect to pH changes. Acetic acid was the major end-product of acidogenic digestion in both reactors, regardless of pH. The percent VFA distribution did not appear to be influenced by pH variation, except for propionic and butyric acids. Besides VFAs, small amounts of formic acid, ethanol, and lactic acid were also formed at all pH values tested.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jctb.280600114
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  • 28
    Electronic Resource
    Electronic Resource
    Microbial metabolism of xenobiotics: Fundamental and applied research (1994)
    Chichester : Wiley-Blackwell
    Journal of Chemical Technology AND Biotechnology 59 (1994), S. 9-23 
    Details
    ISSN: 0268-2575
    Keywords: microbial metabolism ; xenobiotics ; biodegradation ; bioremediation ; bioaugmentation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The ability of microorganisms to metabolise xenobiotic compounds has received much attention due to the environmental persistence and toxicity of these chemicals. The microbial degradation of xenobiotics is seen as a cost effective method of removing these pollutants from the environment by a process now known as bioremediation. Microbial treatment of industrial effluents is also possible. Fundamental work has revealed that a wide variety of microorganisms are capable of degrading an equally wide range of organic pollutants. Pure and mixed cultures of microorganisms have been studied and degradation is observed under both aerobic and anaerobic conditions. Breakdown products have been found during work on the degradative pathways involved and toxicological assessments using bacteria and higher organisms (fish, plants) have been used to determine the toxicity of these intermediates. Many of the degradative genes responsible for xenobiotic metabolism are present on plasmids, transposons or are grouped in clusters on chromosomes. This provides clues to the evolution of degradative pathways and makes the task of genetic manipulation easier such that new microbial strains capable of efficiently degrading pollutants can be developed. Several enzymes involved in xenobiotic metabolism have been isolated and factors affecting their activity investigated. Genetically manipulated strains or naturally isolated organisms may be used in the treatment of industrial wastes or as inocula to enhance degradation in the environment. Environmental factors, including pH, temperature, bioavailability, nutrient supply and oxygen availability have been shown to affect xenobiotic biodegradation. These factors must be optimised to obtain a satisfactory microbial treatment process. Using information gained from fundamental research, bioremediation technology has been used to detoxify different contaminated environments and the results of field studies are very encouraging.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jctb.280590104
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  • 29
    Electronic Resource
    Electronic Resource
    Asymmetric reduction of prochiral ketones by cell-free systems from alcaligenes eutrophus (1994)
    Chichester : Wiley-Blackwell
    Journal of Chemical Technology AND Biotechnology 59 (1994), S. 249-255 
    Details
    ISSN: 0268-2575
    Keywords: Alcaligenes eutrophus ; biodegradation ; nerolidol ; new oxidative pathway ; oxido-reductase ; asymmetric reduction ; terpenoids and steroids ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: A strain of Alcaligenes eutrophus has been isolated from the soil by enrichment culture technique with nerolidol (1), a sesquiterpene alcohol, as the sole source of carbon and energy. Fermentation of nerolidol (1) by this bacterium in a mineral salts medium resulted in the formation of two major metabolites, viz. geranylacetone (2) and an optically active alcohol, (S)-(+)-geranylacetol (3). Nerolidol (1)-induced cells readily transformed 1,2-epoxynerolidol (4) and 1,2-dihydroxynerolidol (5) into geranylacetone (2). These cells also exhibited their ability to carry out stereospecific reduction of 2 into (S)-(+)-geranylacetol (3). Oxygen uptake studies clearly indicated that nerolidol-induced cells oxidized compounds 2, 3, 4, 5 and ethyleneglycol (7). Based on the nature of the metabolites isolated, the ability of nerolidol-induced cells to convert compounds 4 and 5 into geranylacetone (2), and oxygen uptake studies, a pathway for the microbial degradation of nerolidol (1) has been proposed. The proposed pathway envisages the epoxidation of the terminal double bond, opening of the epoxide and cleavage between C-2 and C-3 in a manner similar to the periodate oxidation of cis-diol. The cell-free extract prepared from nerolidol-induced cells readily carried out the asymmetric reduction of compound 2 to an optically active alcohol (3) in the presence of NAD(P)H. The cell-free extract carried out both oxidation and reduction reactions at two different pH values and exhibited wide substrate specificity towards various steroids besides terpenes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jctb.280590307
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  • 30
    Electronic Resource
    Electronic Resource
    Increased biodegradation of a low-density polyethylene (LDPE) matrix in starch-filled LDPE materials (1993)
    Springer
    Journal of polymers and the environment 1 (1993), S. 241-245 
    Details
    ISSN: 1572-8900
    Keywords: Degradation ; biodegradation ; starch-filled ; polyethylene ; prooxidant ; autoxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Preheated14C-labeled LDPE-films with 15% corn starch and a proxidant formulation [masterbatch (MB)] incubated in aqueous solutions with fungi at ambient temperature are about three times more susceptible to biodegradation than the corresponding preheated pure LDPE as observed by liquid scintillation counting (LSC). The inbuilt induction time before autoxidation commences can be shortened by initial heating. Preheated LDPE-MB materials biodegrade about five times faster than nonheated ones. After 1 year of biodegradation of nonheated LDPE-MB, sporadic increases in the evolution of14CO2 have been noted, showing that the induction time may be running toward and end.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01458290
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  • 31
    Electronic Resource
    Electronic Resource
    Biodegradable water-soluble polycarboxylic acid design: Biodegradability and builder performance in detergent formulation of partially dicarboxylated polyuronide containing sugar residues in the backbone (1993)
    Springer
    Journal of polymers and the environment 1 (1993), S. 23-29 
    Details
    ISSN: 1572-8900
    Keywords: Partially dicarboxylated polyuronide ; biodegradation ; design ; pectic acid ; alginic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Partially dicarboxylated polyuronide having a variable amount of unreacted sugar blocks as an enzymatically cleavable segment was prepared by the controlled oxidation of pectic acid and alginic acid. It was found that partially dicarboxylated polyuronides containing uronide blocks showed better biodegradability than those having no uronide block in the polycarboxylate chain. The rate of biodegradation varies according to the degree of dicarboxylation. It was confirmed that dicarboxy polyuronides containing more than 70% unreacted uronide residues tended to biodegrade quickly. The biodegradability obtained by the BOD test and the enzymatic degradability are well correlated, suggesting that these polymers are first cleaved at the sugar blocks by carbohydrase with subsequent assimilation of the resultant oligomeric fractions. Detergency was dependent on the content of the carboxylate groups in the polymer. The polymers with high carboxylate contents showed better builder performance. The detergency of dicarboxy pectic acid was better than that of dicarboxy alginic acid when compared on the basis of an equal degree of dicarboxylation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01457650
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  • 32
    Electronic Resource
    Electronic Resource
    Degradation of poly(β-hydroxyalkanoates) and polyolefin blends in a municipal wastewater treatment facility (1993)
    Springer
    Journal of polymers and the environment 1 (1993), S. 269-274 
    Details
    ISSN: 1572-8900
    Keywords: Poly(β-hydroxyalkanoates) ; biodegradation ; activated sludge ; starch-polyolefin blends
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Six types of plastics and plastic blends, the latter composed at least partially of biodegradable material, were exposed to aerobically treated wastewater (activated sludge) to ascertain their biodegradability. In one study, duplicate samples of 6% starch in polypropylene, 12% starch in linear low-density polyethylene, 30% polycaprolactone in linear low-density polyethylene, and poly(β-hydroxybutyrate-co-hydroxyvalerate) (PHB/V), a microbially produced polyester, were exposed to activated sludge for 5 months, and changes in mass, molecular weight average, and tensile properties were measured. None of the blended material showed any sign of degradation. PHB/V, however, showed a considerable loss of mass and a significant loss of tensile strength. In a second study, PHB/V degraded rapidly, but another type of microbial polymer which forms a thermoplastic elastomer, poly(β-hydroxyoctanoate), did not degrade. These results illustrate the potential for disposal and degradation of PHB/V in municipal wastewater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01458293
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  • 33
    Electronic Resource
    Electronic Resource
    Bioavailability of sorbed- and separate-phase chemicals (1993)
    Springer
    Biodegradation 4 (1993), S. 141-153 
    Details
    ISSN: 1572-9729
    Keywords: bioavailability ; biodegradation ; sorption ; oil ; soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695116
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  • 34
    Electronic Resource
    Electronic Resource
    Effect of hydrogen peroxide on the biodegradation of PCBs in anaerobically dechlorinated river sediments (1993)
    Springer
    Biodegradation 4 (1993), S. 241-248 
    Details
    ISSN: 1572-9729
    Keywords: aerobic ; anaerobic ; biodegradation ; hydrogen peroxide ; polychlorinated biphenyls ; sequential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The ability to initiate aerobic conditions in dechlorinated anaerobic sediments was tested using hydrogen peroxide as an oxygenation agent. Hydrogen peroxide additions to the sediment induced aerobic polychlorinated biphenyl (PCB) degraders as indicated first, by an increase in bacterial count and second by a decline in PCB concentration from 135 µg/g to 20 µg/g over a 96-day period. Dechlorinated anaerobic sediment seems also to harbor indigenous anaerobic and aerobic microorganisms with high PCB degradation abilities. Those results support the potential ofin situ degradation of PCBs using a sequential anaerobic-aerobic technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695972
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  • 35
    Electronic Resource
    Electronic Resource
    Microbiological aspects of the removal of chlorinated hydrocarbons from air (1993)
    Springer
    Biodegradation 4 (1993), S. 261-282 
    Details
    ISSN: 1572-9729
    Keywords: chlorinated hydrocarbons ; biodegradation ; biotransformation ; cometabolism ; gaseous emissions ; waste gas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Chlorinated hydrocarbons are widely used synthetic chemicals that are frequently present in industrial emissions. Bacterial degradation has been demonstrated for several components of this class of compounds. Structural features that affect the degradability include the number of chlorine atoms and the presence of oxygen substituents. Biological removal from waste streams of compounds that serve as a growth substrate can relatively easily be achieved. Substrates with more chlorine substituents can be converted cometabolically by oxidative routes. The microbiological principles that influence the biodegradability of chlorinated hydrocarbons are described. A number of factors that will determine the performance of microorganisms in systems for waste gas treatment is discussed. Pilot plant evaluations, including economics, of a biological trickling filter for the treatment of dichloromethane containing waste gas indicate that at least for this compound biological treatment is cost effective.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695974
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  • 36
    Electronic Resource
    Electronic Resource
    Degradation of 2-sec-butylphenol: 3-sec-butylcatechol,2-hydroxy-6-oxo-7-methylnona-2,4-dienoic acid, and 2-methylbutyric acid as intermediates (1993)
    Springer
    Biodegradation 4 (1993), S. 81-89 
    Details
    ISSN: 1572-9729
    Keywords: 2-sec-butylphenol ; 3-sec-butylcatechol ; biodegradation ; meta-cleavage product ; monooxygenase ; metapyrocatechase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Pseudomonas sp. strain HBP1 Prp, a mutant of strain HBP1 that was originally isolated on 2-hydroxybiphenyl, was able to grow on 2-sec-butylphenol as the sole carbon and energy source. During growth on 2-sec-butylphenol, 2-methylbutyric acid transiently accumulated in the culture medium. Its concentration reached a maximum after 20 hours and was below detection limit at the end of the growth experiment. The first three enzymes of the degradation pathway — a NADH-dependent monooxygenase, a metapyrocatechase, and ameta-fission product hydrolase — were partially purified. The product of the the monooxygenase reaction was identified as 3-sec-butylcatechol by mass spectrometry. This compound was a substrate for the metapyrocatechase and was converted to 2-hydroxy-6-oxo-7-methylnona-2,4-dienoic acid which was identified by gas chromatography-mass spectrometry of its trimethylsilyl-derivative. The cofactor independentmeta-cleavage product hydrolase used 2-hydroxy-6-oxo-7-methylnona-2,4-dienoic acid as a substrate. All three enzymes showed highest activities for 2-hydroxybiphenyl and its metabolites, respectively, indicating that 2-sec-butylphenol is metabolized via the same pathway as 2-hydroxybiphenyl.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702324
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  • 37
    Electronic Resource
    Electronic Resource
    A microbial biosensor system for dihalomethanes (1993)
    Springer
    Biodegradation 4 (1993), S. 101-105 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; biosensor ; dechlorination ; dehalogenase ; dichloromethane ; Hyphomicrobium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A biosensor system able to measure dichloromethane (DCM) and other dihalomethanes has been developed. The analysis is based on Hyphomicrobium DM2 cells immobilized in alginate. A combination of transducers consisting of a flow-calorimeter followed by a chloride-sensitive electrode has been used. By this design it was possible to monitor different aspects of the cell metabolism from one and the same pulse of substrate. The detection limit for the biosensor was 0.1 µM dichloromethane. The biosensor system can be used for continuous measurements in a sample stream.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702326
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  • 38
    Electronic Resource
    Electronic Resource
    Synergistic interaction between two bacterial isolates in the degradation of carbofuran (1993)
    Springer
    Biodegradation 4 (1993), S. 115-123 
    Details
    ISSN: 1572-9729
    Keywords: insecticides ; methylcarbamates ; carbofuran ; carbaryl ; bendiocarb ; carbosulfan ; biodegradation ; bacterial degradation ; synergism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The dominant bacteriaPseudomonas sp. andArthrobacter sp. were isolated from the standing water of carbofuran-retreatedAzolla plot.Arthrobacter sp. hydrolysed carbofuran added to the mineral salts medium as a sole source of carbon and nitrogen while no degradation occurred withPseudomonas sp. Interestingly, when the medium containing carbofuran was inoculated with bothArthrobacter sp. andPseudomonas sp., a synergistic increase in its hydrolysis and subsequent release of CO2 from the side chain was noticed. This synergistic interaction was better expressed at 25° C than at 35° C. Likewise, related carbamates, carbaryl, bendiocarb and carbosulfan were more rapidly degraded in the combined presence of both bacterial isolates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702328
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  • 39
    Electronic Resource
    Electronic Resource
    Degradation of the insecticide Hydramethylnon byPhanerochaete chrysosporium (1993)
    Springer
    Biodegradation 4 (1993), S. 131-139 
    Details
    ISSN: 1572-9729
    Keywords: Hydramethylnon ; insecticide ; lignin peroxidase ; biodegradation ; Phanerochaete chrysosporium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The decomposition of the amidinohydrazone-type insecticide Hydramethylnon (HMN) by soil fungi has been investigated. A simple spectrophotometric method was developed for the estimation of HMN in soil and fungal culture media. HMN was found to be degraded in soil with a half life of 14 to 25 days. Degradation of HMN by the lignolytic fungus,Phanerochaete chrysosporium yielded two major breakdown products;p-(trifluoromethyl)-cinnamic acid (TFCA) andp-(trifluoromethyl)-benzoic acid (TFBA). TFCA was converted to TFBA which was subsequently metabolised via themeta-fission pathway. Fluoride release from HMN could not be detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702330
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  • 40
    Electronic Resource
    Electronic Resource
    Aerobic, phenol-induced TCE degradation in completely mixed, continuous-culture reactors (1993)
    Springer
    Biodegradation 4 (1993), S. 59-69 
    Details
    ISSN: 1572-9729
    Keywords: trichloroethylene (TCE) ; biodegradation ; phenol ; Pseudomonas ; induction ; cometabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract BothPseudomonas putida F1 and a mixed culture were used to study TCE degradation in continuous culture under aerobic, non-methanotrophic conditions. TCE mass balance studies were performed with continuous culture reactors to determine the total percent removed in the reactors, and to quantify the percent removed by air stripping and biodegradation. Adsorption of TCE to biomass was assumed to be negligible. This research demonstrated the feasibility of treating TCE-contaminated water under aerobic, non-methanotrophic conditions with a mixed-culture, continuous-flow system. Initially glucose and acetate were fed as primary substrates. Pnenol, which has been shown to induce TCE-degrading enzymes, was fed at a much lower concentration (20mg/L). Little degradation of TCE was observed when acetate and glucose were the primary substrates. After omitting glucose and acetate from the feed and increasing the phenol concentration to 50mg/L, TCE biotransformation was observed at a significant level (46%). When the phenol concentration in the feed was increased to 420mg/L, 85% of the incoming TCE was estimated to have been biodegraded. Under the same conditions, phenol utilization by the mixed culture was greater than that ofP. putida F1, and TCE degradation by the mixed culture (85%) exceeded that ofP. putida F1 (55%). The estimated percent-of-TCE biodegraded by the mixed culture was consistently greater than 80% when phenol was fed at 420mg/L. Biodegradation of TCE was also observed in mixed-culture, batch experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00701455
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  • 41
    Electronic Resource
    Electronic Resource
    Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer (1993)
    Springer
    Biodegradation 4 (1993), S. 249-259 
    Details
    ISSN: 1572-9729
    Keywords: aromatic hydrocarbons ; biodegradation ; bioremediation ; denitrification ; groundwater ; Pseudomonas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We characterized bacteria from contaminated aquifers for their ability to utilize aromatic hydrocarbons under hypoxic (oxygen-limiting) conditions (initial dissolved oxygen concentration about 2 mg/l) with nitrate as an alternate electron acceptor. This is relevant to current intense efforts to establish favorable conditions forin situ bioremediation. Using samples of granular activated carbon slurries from an operating groundwater treatment system, we isolated bacteria that are able to use benzene, toluene, ethylbenzene, orp-xylene as their sole source of carbon under aerobic or hypoxic-denitrifying conditions. Direct isolation on solid medium incubated aerobically or hypoxically with the substrate supplied as vapor yielded 103 to 105 bacteria ml−1 of slurry supernatant, with numbers varying little with respect to isolation substrate or conditions. More than sixty bacterial isolates that varied in colony morphology were purified and characterized according to substrate utilization profiles and growth condition (i.e., aerobic vs. hypoxic) specificity. Strains with distinct characteristics were obtained using benzene compared with those isolated on toluene or ethylbenzene. In general, isolates obtained from direct selection on benzene minimal medium grew well under aerobic conditions but poorly under hypoxic conditions, whereas many ethylbenzene isolates grew well under both incubation conditions. We conclude that the conditions of isolation, rather than the substrate used, will influence the apparent characteristic substrate utilization range of the isolates obtained. Also, using an enrichment culture technique, we isolated a strain ofPseudomonas fluorescens, designated CFS215, which exhibited nitrate dependent degradation of aromatic hydrocarbons under hypoxic conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695973
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  • 42
    Electronic Resource
    Electronic Resource
    Synthesis of copolymers composed of 2-methylene-1,3,6-trioxocane and vinyl monomers and their enzymatic degradation (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 3159-3163 
    Details
    ISSN: 0887-624X
    Keywords: radical ring-opening polymerization ; ketene acetal ; biodegradation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311233
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  • 43
    Electronic Resource
    Electronic Resource
    Degradation of nitriles and amides by the immobilized cells of Pseudomonas putida (1993)
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 483-486 
    Details
    ISSN: 1573-0972
    Keywords: Acetonitrile ; amides ; biodegradation ; immobilization ; nitriles ; Pseudomonas putida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Pseudomonas putida, capable of utilizing acetonitrile as a sole source of C and N, was immobilized in calcium alginate and the rates of degradation of nitriles, including acetonitrile, and their respective amides were studied. All the organic nitriles and amides tested were converted into NH3 and CO2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328038
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  • 44
    Electronic Resource
    Electronic Resource
    Biofiltration of methanol vapor (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 512-524 
    Details
    ISSN: 0006-3592
    Keywords: biofiltration ; biofilter modeling ; methanol ; biodegradation ; VOC emissions ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biofiltration of solvent and fuel vapors may offer a costeffective way to comply with increasingly strict air emission standards. An important step in the development of this technology is to derive and validate mathematical models of the biofiltration process for predictive and scaleup calculations. For the study of methanol vapor biofiltration, an 8-membered bacterial consortium was obtained from methanol-exposed soil. The bacteria were immobilized on solid support and packed into a 5-cm-diameter, 60-cm-high column provided with appropriate flowmeters and sampling ports. The solid support was prepared by mixing two volumes of peat with three volumes of perlite particles (i.e., peat-perlite volume ratio 2:3). Two series of experiments were performed. In the first, the inlet methanol concentration was kept constant while the superficial air velocity was varied from run to run. In the second series, the air flow rate (velocity) was kept constant while the inlet methanol concentration was varied. The unit proved effective in removing methanol at rates up to 112.8 g h-1 m-3 packing. A mathematical model has been derived and validated. The model described and predicted experimental results closely. Both experimental data and model predictions suggest that the methanol biofiltration process was limited by oxygen diffusion and methanol degradation kinetics. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410503
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  • 45
    Electronic Resource
    Electronic Resource
    Criteria to assess when biodegradation is kinetically limited by intraparticle diffusion and sorption (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 625-632 
    Details
    ISSN: 0006-3592
    Keywords: bioremediation ; biodegradation ; soil ; sorption/desorption ; intraparticle diffusion ; pollution ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To determine when intraparticle diffusion and sorption can influence the rate of biodegradation, we consider the biodegradation of a pollutant diffusing into or out of porous aggregates suspended in a liquid medium, where the reactant is metabolized by bacteria. The pollutant that diffuses into the aggregates obeys a sorption-desorption equilibrium isotherm at sites on inner pore surfaces. The governing partial differential equations for the transient process describe (a) the local equilibrium sorption-desorption and the diffusion of the pollutant in the porous aggregate, (b) the mass transfer of the pollutant from the external surface of the spherical aggregates to the reaction medium, and (c) the biodegradation of the pollutant in the external medium. Illustrative calculations are presented for a linear sorption calculations are presented for a linear sorption isotherm and first-order biodegradation kinetics. A dimensionless group, comprised of the diffusion coefficient, biodegradation rate coefficient, aggregate characteristics length (radius), and adsorption capacity, serves as a criterion for determining when intraparticle diffusion can be ignored. The model provides a realistic description of experimental data for biodegradation of a pollutant subject to intraparticle diffusion and sorption. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410605
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  • 46
    Electronic Resource
    Electronic Resource
    Phenol removal from waste gases with a biological filter by Pseudomonas putida (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 693-699 
    Details
    ISSN: 0006-3592
    Keywords: phenol ; biodegradation ; biofilter ; Pseudomonas putida ; deodorization ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The purpose of this study is to investigate the feasibility of biologically removing phenol from waste gases by means of a biofilter using a Pseudomonas putida strain. Two series of both batch and continuous tests have been performed in order to ascertain the microbial degradation of phenol. For the preliminary batch tests, carried out in order to test the effective feasibility of the process and to investigate their kinetic behavior, two different microbial cultures belonging to the Pseudomonas genus have been employed, a heterogeneous culture and a pure strain of P. putida. The results of these comparative investigation showed that the pure culture is more efficient than the mixed one, even when the latter has undergone three successive acclimatization tests. The continuous experiments have been conducted during a period of about 1 year in a laboratory-scale column, packed with a mixture of peat and glass beads, and utilizing the pure culture of P. putida as microflora and varying the inlet phenol concentration from 50 up to 2000 mg m-3. The results obtained show that high degrees of conversion can be obtained (0.93/0.996) operating at a residence time of 54 s. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410703
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  • 47
    Electronic Resource
    Electronic Resource
    Competition between two microbial populations in a sequencing fed-batch reactor: Theory, experimental verification, and implications for waste treatment applications (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 643-656 
    Details
    ISSN: 0006-3592
    Keywords: biodegradation ; microbial competition ; sequencing fed-batch reactor ; phenol ; wastewater treatment ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Competition between two microbial populations for a single pollutant (phenol) was studied in a sequencing fed-batch reactor (SFBR). A mathematical model describing this system was developed and tested experimentally. It is based on specific growth rate expressions revealed from pure culture batch experiments. The species employed were Pseudomonas putida (ATCC 17514) and Pseudomonas resinovorans (ATCC 14235). It was found that both species biodegrade phenol following inhibitory kinetics which can be described by Andrews' expression. The model predicts that the dynamics of a SFBR, and the kinetics of biodegradation, result in a complex set of operating regimes in which neither species, only one species, or both species can survive at steady cycle. The model also predicts the existence of multiple outcomes, achievable from different start-up conditions, in some domains of the operating parameter space. Experimental results confirmed the model predictions. There was excellent agreement between predicted and measured concentrations of phenol, total biomass, and the biomass of each individual species. This study shows how serious discrepancies can arise in scale-up of biodegradation data if population dynamics are not taken into account. It also further confirms experimentally the theory of microbial competition in periodically forced bioreactors. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420513
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  • 48
    Electronic Resource
    Electronic Resource
    Biodegradation of an inhibitory nongrowth substrate (nitroglycerin) in batch reactors (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 41 (1993), S. 79-87 
    Details
    ISSN: 0006-3592
    Keywords: acclimation ; biodegradation ; cometabolism ; ethyl acetate ; explosives ; nitroglycerin ; nongrowth substrate ; primary substrate ; priority pollutants ; sequencing batch reactors ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biodegradation of nitroglycerin (NG), an inhibitory, nongrowth substrate present in a multicomponent munition wastewater, was investigated in a pilot-scale batch reactor operated with both aerobic and anoxic cycles. A mixed culture was initially acclimated by gradual introduction of NG into influent and subsequently exposed to actual NG-laden production wastewater. System performance revealed that NG was amenable to aerobic biodegradation without adverse impact on removal efficiencies of other pollutants. Temporal NG concentration profiles indicated that an influent concentration of approximately 200 mg/L of NG was reduced to below detection limits in less than 5 h of aeration with no appreciable (〈4%) biosorption. Failure of NG-acclimated cultures to utilize NG as a sole carbon source in bench-scale reactors suggested that NG behaved as a non-growth substrate and its degradation possibly occurred by cometabolism. Ethyl acetate present in the waste stream was an adequate growth substrate in terms of both biological and physicochemical properties. High concentrations of NO3-N, produced as a result of aerobic degradation of NG and other nitrogenous compounds of the waste, were treated in an anoxic phase. Approximately 95 mg/L of NO3-N was denitrified to below detection limits in 5 h of anoxia without the addition of external carbon sources. Two SRB cycle schemes with different static-fill times exhibited significant differences in treatment efficiencies. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260410111
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  • 49
    Electronic Resource
    Electronic Resource
    TCE degradation in a methanotrophic attached-film bioreactor (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 859-872 
    Details
    ISSN: 0006-3592
    Keywords: methanotroph ; trichloroethane ; expanded bed ; attached film ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Trichloroethene was degraded in expanded-bed bioreactors operated with mixed-culture methanotrophic attached films. Biomass concentrations of 8 to 75 g volatile solids (VS) per liter static bed (Lsb) were observed. Batch TCE degradation rates at 35°C followed the Michaelis-Menten model, and a maximum TCE degradation rate (qmax) of 10.6 mg TCE/gVS · day and a half velocity coefficient (KS) of 2.8 mg TCE/L were predicted. Continuous-flow kinetics also followed the Michaelis-Menten model, but other parameters may be limiting, such as dissolved copper and dissolved methane - qmax and KS were 2.9 mg TCE/gVS · day and 1.5 mg TCE/L, respectively, at low copper concentrations (0.003 to 0.006 mg Cu/L). The maximum rates decreased substantially with small increases in dissolved copper. Methane consumption during continuous-flow operation varied from 23 to 1200 g CH4/g TCE degraded. Increasing the influent dissolved methane concentration from 0.01 mg/L to 5.4 mg/L reduced the TCE degradation rate by nearly an order of magnitude at 21°C. Exposure of biofilms to 1.4 mg/L tetrachloroethene (PCE) at 35°C resulted in the loss of methane utilization ability. Tests with methanotrophs grown on granular activated carbon indicated that lower effluent TCE concentrations could be obtained. The low efficiencies of TCE removal and low degradation rates obtained at 35°C suggest that additional improvements will be necessary to make methanotrophic TCE treatment attractive. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420711
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  • 50
    Electronic Resource
    Electronic Resource
    Confusion between dimethyl selenenyl sulfide and dimethyl selenone released by bacteria (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 7 (1993), S. 335-342 
    Details
    ISSN: 0268-2605
    Keywords: Bioremediation ; biodegradation ; dimethyl selenenyl sulfide ; biomethylation ; pathway ; chemiluminescence ; micro-organism ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dimethyl selenone [(CH3)2SeO2] has been reported in the literature as a metabolite released by bacteria in contact with selenium metal or selenium salts. In this study, mass spectral, chromatographic, and boiling-point data are presented that show that dimethyl selenone has been confused with dimethyl selenenyl sulfide (CH3SeSCH3). In addition, the headspaces above monocultures of selenium-resistant bacteria were examined using gas chromatography followed by fluorine-induced chemiluminescence detection. A number of alkyl sulfur and selenium species were detected, along with dimethyl selenenyl sulfide. A pathway from oxidized selenium salts to reduced methylated selenides and dimethyl selenenyl sulfide is also presented.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590070507
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  • 51
    Electronic Resource
    Electronic Resource
    Biodegradation of haloalkanes (1992)
    Springer
    Biodegradation 3 (1992), S. 299-313 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; bromoalkanes ; dehalogenase ; environmental pollution ; haloalkanes ; Pseudomonas sp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Halogenated alkanes constitute a significant group among the organic pollutants of environmental concern. Their industrial and agricultural uses are extensive, but until 1978 they were considered to be non-biodegradable. In recent years, microorganisms were described that could degrade, partially or fully, singly or in consortia, many of the compounds tested. The first step in haloalkane degradation appears to be universal: removal of the halogen atom(s). This is mediated by a group of enzymes, generally known as dehalogenases, acting in most cases either as halidohydrolases or oxygenases. Nevertheless, information is still severely lacking regarding the biochemical pathways involved in these processes, as well as their genetic control. A recently isolated Pseudomonas strain, named ES-2, was shown to possess a very wide degradative spectrum, and to contain at least one hydrolytic dehalogenase. The utilization by this organism of water-insoluble haloalkanes, such as 1-bromooctane, appears to consist of three phases: extracellular emulsification by a constitutively excreted surface active agent, periplasmic dehalogenation by an inducible dehalogenase, and intracellular degradation of the residual carbon skeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00129090
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    Electronic Resource
    Electronic Resource
    Metabolic pathway for the biodegradation of octadecylbis(2-hydroxyethyl)amine (1992)
    Springer
    Biodegradation 3 (1992), S. 435-443 
    Details
    ISSN: 1572-9729
    Keywords: octadecylbis(2-hydroxyethyl)amine ; non-ionic surfactant ; biodegradation ; metabolism ; central fission ; diethanolamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The biodegradation curve of octadecylbis(2-hydroxyethyl)amine determined in a Closed Bottle test suggested an initial oxidation of the alkyl chain and a subsequent degradation of the diethanolamine formed. Using the sludge from the test as inoculum, a bacterium capable of utilizing octadecylbis(2-hydroxyethyl)amine as sole source of carbon and energy was isolated. This bacterium also utilized various other alkylbis(2-hydroxyethyl)amines and octadecylpolyoxyethylene(5)amide. Respirometric studies and the formation of diethanolamine by a washed cell suspension of the pure culture showed that the bacterium only oxidized the alkyl chain. Furthermore, in cell-free extracts a dehydrogenase activity catalysing the oxidation of octadecylbis(2-hydroxyethyl)amine was detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240365
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  • 53
    Electronic Resource
    Electronic Resource
    Biodiversity amongst filamentous fungi (1992)
    Springer
    Biodiversity and conservation 1 (1992), S. 293-311 
    Details
    ISSN: 1572-9710
    Keywords: fungi ; molecular biology ; ultrastructure ; secondary metabolites ; plant pathogens ; coevolution ; biodegradation ; symbiosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Diversities in fungi are manifold. Fungi themselves are heterogeneous and constitute at least three unrelated major taxa. Structural diversity reflects, in most cases, adaptive and functional strategies. Diversity in nucleic acids and chemical compounds is very high in several fungal taxa. Fungi play an essential role in the function of ecosystems. The diversity of plant parasites is extremely high and species-dependent associations exist. Saprobic fungi are most important in wood and litter decay and diverse taxa comprise the main decomposers in specific successional niches. Two dominating symbiotic systems have evolved convergently in various fungal groups, notably lichens and mycorrhizas, both remarkably diverse in their heterotrophic partners.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00693766
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  • 54
    Electronic Resource
    Electronic Resource
    The effects of Fusarium oxysporum f.sp. lycopersici (Sacc.) Snyder & Hansen on tomato in diphenamid-treated soil (1992)
    Springer
    Mycopathologia 119 (1992), S. 35-41 
    Details
    ISSN: 1573-0832
    Keywords: Fusarium-wilt pathogen ; Lycopersicon esculentum ; diphenamid ; growth responses ; rhizosphere ; biodegradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Pre-emergence soil application of the herbicide diphenamid in concentrations exceeding the normal field rate increased the resistance of tomato plants towards infection by the wilt fungus Fusarium oxysporum f.sp. lycopersici. This was detected as significant increases in the percentage emergence of seedlings although growth parameters of the raised seedlings were reduced. Treated plants exhibited no wilt symptoms, although the pathogen maintained its population at detectable levels in the rhizosphere of tomato plants. However, the growth inhibition caused by diphenamid alone was much less than that reported for the combined application of pathogen and herbicide. Growth activities of F. oxysporum f.sp. lycopersici were inhibited by high concentrations of diphenamid in vitro. It is possible that the biodegradation of this herbicide by species such as Aspergillus candidus (present in substantial counts in treated rhizospheres) was one of the causes of increased tolerence of the pathogen to the herbicide in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00492228
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  • 55
    Electronic Resource
    Electronic Resource
    Characterization of an inducible, membrane-bound iminodiacetate dehydrogenase from Chelatobacter heintzii ATCC 29600 (1992)
    Springer
    Biodegradation 3 (1992), S. 423-434 
    Details
    ISSN: 1572-9729
    Keywords: membrane protein ; biodegradation ; iminodiacetate ; iminodiacetate dehydrogenase ; nitrilotriacetate (NTA) ; ubiquinones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Iminodiacetate (IDA) is a xenobiotic intermediate common to both aerobic and anaerobic metabolism of nitrilotriacetate (NTA). It is formed by either NTA monooxygenase or NTA dehydrogenase. In this paper the detection and characterization of a membrane-bound iminodiacete dehydrogenase (IDA-DH) from Chelatobacter heintzii ATCC 29600 is reported, which oxidizes IDA to glycine and glyoxylate. Out of 15 compounds tested, IDA was the only substrate for the enzyme. Optimum activity of IDA-DH was found at pH 8.5 and 25°C, respectively, and the Km for IDA was found to be 8mM. Activity of the membrane-bound enzyme was inhibited by KCN, antimycine and dibromomethylisopropyl-benzoquinone. When inhibited by KCN IDA-DH was able to reduce the artificial electron acceptor iodonitrotetrazolium (INT). It was possible to extract IDA-DH from the membranes with 2% cholate, to reconstitute the enzyme into soybean phospholipid vesicles and to obtain IDA-DH activity (more than 50% recovery) using ubiquinone Q1 as the intermediate electron carrier and INT as the final electron acceptor. Growth experiments with different substrates revealed that in all NTA-degrading strains tested both NTA monooxygenase and IDA-DH were only expressed when the cells were grown on NTA or IDA. Furthermore, in Cb. heintzii ATCC 29600 growing exponentially on succinate and ammonia, addition of 0.4 g l-1 NTA led to the induction of the two enzymes within an hour and NTA was utilized simultaneously with succinate. The presence of IDA-DH was confirmed in ten different NTA-degrading strains belonging to three different genera.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240364
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  • 56
    Electronic Resource
    Electronic Resource
    Microbes and microbial enzymes for cyanide degradation (1992)
    Springer
    Biodegradation 3 (1992), S. 3-18 
    Details
    ISSN: 1572-9729
    Keywords: hydrogen cyanide ; enzyme mechanisms ; biodegradation ; microbes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Cyanide is an important industrial chemical produced on a grand scale each year. Although extremely toxic to mammalian life, cyanide is a natural product generated by fungi and bacteria, and as a result microbial systems have evolved for the degradation of cyanide to less toxic compounds. The enzymes which utilize cyanide as a substrate can be categorized into the following reaction types: substitution/addition, hydrolysis, oxidation, and reduction. Each of these categories is reviewed with respect to the known biochemistry and feasibility for use in treatment of cyanide containing wastes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189632
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  • 57
    Electronic Resource
    Electronic Resource
    A mechanistic perspective on bacterial metabolism of chlorinated methanes (1992)
    Springer
    Biodegradation 3 (1992), S. 19-36 
    Details
    ISSN: 1572-9729
    Keywords: chloromethanes ; chlorofluoromethanes ; mechanisms ; bacteria ; dehalogenation ; biodegradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Chlorinated methanes are important environmental pollutants, which can be metabolized by bacteria. The biotransformation of chlorinated methanes by bacteria has been shown to be due either to gratuitous metabolism (cometabolism) or their use as a source of carbon and energy. The reactions which result in carbon-halogen bond cleavage include substitutive, reductive, oxygenative, and gem-elimination mechanisms. Certain methylotrophic bacteria can use dichloromethane as a source of carbon and energy. Dichloromethane dehalogenase catalyzes the first substitutive reaction in this metabolism. The enzyme shows a 1010-fold rate enhancement over the reaction of the bisulfide anion with dichloromethane in water. Pseudomonas putida G786 synthesizes cytochrome P-450CAM which catalyzes the gratuitous reduction of chlorinated methanes. These studies with purified enzymes are beginning to reveal more detailed mechanistic features of bacterial chlorinated methane metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189633
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  • 58
    Electronic Resource
    Electronic Resource
    Biodegradation of short-chain alkyl sulphates by a coryneform species (1992)
    Springer
    Biodegradation 3 (1992), S. 83-91 
    Details
    ISSN: 1572-9729
    Keywords: alkylsulphatase ; alkyl sulphate ; biodegradation ; desulphation ; hydrolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Coryneform B1a isolated from soil grew well on butyl-, pentyl- and hexyl-1-sulphates esters and on the corresponding parent alcohols as sole sources of carbon, with growth rates around 0.14–0.19 h-1. Propyl-1-sulphate and heptyl-1-sulphate supported slower growth, and their C1, C2 and C8 homologues were not utilised at all. Growth of the organism was accompanied by disappearance of butyl-1-sulphate. In the presence of resting cells, butyl-1-sulphate degradation was stoichiometric with the liberation of inorganic sulphate. Butan-1-ol was also detected but in less than stoichiometric amounts. Non-denaturing polyacrylamide gel electrophoresis of extracts of cells grown on butyl-1-sulphate, followed by incubation of gels in butyl-1-sulphate and precipitation of liberated SO4 2- as BaSO4, revealed a single white band of alkylsulphatase activity. Other zymograms produced in the same way but incubated with the C5 and C6 esters, each produced a single band of the same mobility and intensity. With the C3 and C7 homologues, the same band was present but considerably less intense. No alkylsulphatase band was detected for methyl, ethyl or octyl-1-sulphates. Assays of alkylsulphatase activity in crude cell-extracts indicated maximum activity towards butyl-1-sulphate at pH 7.5 and 30° C, with Km=8.4±1.4 mM and V max =0.13±0.01 μmol/min/mg of protein. The results indicated that degradation of short-chain alkyl sulphates in this organism was initiated by enzymic hydrolysis to the corresponding alcohol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189636
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    Electronic Resource
    The environment, microbes and bioremediation: microbial activities modulated by the environment (1992)
    Springer
    Biodegradation 3 (1992), S. 125-135 
    Details
    ISSN: 1572-9729
    Keywords: natural evolution ; directed evolution ; biodegradation ; environmental pollutants ; environmental signal transduction ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Microorganisms in nature are largely responsible for the biodegradation and removal of toxic and non-toxic chemicals. Many organisms are also known to have specific ecological niches for proliferation and colonization. The nature of the environment dictates to a large extent the biodegradability of synthetic compounds by modulating the evolutionary processes in microorganisms for new degradative genes. Similarly, environmental factors often determine the extent of microbial gene expression by activating or repressing specific gene or sets of genes through a sensory signal transduction process. Understanding how the environment modulates microbial activity is critical for successful bioremediative applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00129078
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  • 60
    Electronic Resource
    Electronic Resource
    Biodegradation of polycyclic aromatic hydrocarbons (1992)
    Springer
    Biodegradation 3 (1992), S. 351-368 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; degradation ; detoxification ; dioxygenase ; hydroxylation ; monooxygenase ; polycyclic aromatic hydrocarbons ; ring cleavage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons. A catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds. Molecular oxygen is essential for the initial hydroxylation of polycyclic aromatic hydrocarbons by microorganisms. In contrast to bacteria, filamentous fungi use hydroxylation as a prelude to detoxification rather than to catabolism and assimilation. The biochemical principles underlying the degradation of polycyclic aromatic hydrocarbons are examined in some detail. The pathways of polycyclic aromatic hydrocarbon catabolism are discussed. Studies are presented on the relationship between the chemical structure of the polycyclic aromatic hydrocarbon and the rate of polycyclic aromatic hydrocarbon biodegradation in aquatic and terrestrial ecosystems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00129093
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  • 61
    Electronic Resource
    Electronic Resource
    Modification of polyolefin surfaces with iron cluster oxidants (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 389-396 
    Details
    ISSN: 0887-624X
    Keywords: polyethylene ; polypropylene ; oxidation ; biodegradation ; C—H bond activation ; functionalization ; XPS ; ATR-IR ; surface ; Gif ; oxidase ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Modification of polyethylene and polypropylene film and powder surfaces with oxygen and hydrogen peroxide is promoted by nonporphyrinic, nonfree radical based iron reagents such as Fe3O(OCOCH3)6(C6H5N)3.5 and FeCl3 • 6H2O/picolinic acid. These oxidation systems introduced small amounts of carbonyl groups onto the surface of these hydrocarbon polymers. The most visible manifestation of this reaction was increased polyolefin wettability toward water. IR spectroscopy, XPS spectroscopy, and chemical derivatization all were used to verify that the reaction had occurred and that a chemically derivatizable surface had been prepared. The overall process produced a fraction of the density of functional groups introduced by conventional etching chemistry.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300306
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  • 62
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    Electronic Resource
    Colonic Drug Delivery: Enhanced Release of Indomethacin from Cross-Linked Chondroitin Matrix in Rat Cecal Content (1992)
    Springer
    Pharmaceutical research 9 (1992), S. 276-278 
    Details
    ISSN: 1573-904X
    Keywords: colonic delivery ; colon ; chondroitin sulfate ; biodegradation ; drug delivery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018910128452
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  • 63
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    Electronic Resource
    A novel bioreactor for the biodegradation of inhibitory aromatic solvents: Experimental results and mathematical analysis (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 1403-1411 
    Details
    ISSN: 0006-3592
    Keywords: aromatic solvents ; bioreactor ; benzene ; toluene ; xylene ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel bioreactor for the biodegradation of toxic aromatic solvents, such as benzene, toluene, and xylenes in liquid effluent stream, was developed. Silicon tubing was immersed in the completely mixed and aerated bioreactor, and liquid toluene as a model solvent was circulated within the tubing. Toluene diffused out of the tube wall and was transferred at high rate into the culture broth, where biodegradation occurred. The effect of operating parameters on the toluene transfer rate was investigated. During continuous operation, the biodegradation rate was considerably higher than those obtained using conventional methods. A mathematical model was established for continuous biodegradation, and simulation results coincided with the experimental results. The performance and operational criteria of the bioreactor were analyzed on the basis of both the experimental and simulation results. © 1992 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260401115
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  • 64
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    Electronic Resource
    Mineralization of biphenyl and PCBs by the white rot fungus Phanerochaete chrysosporium (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 40 (1992), S. 1395-1402 
    Details
    ISSN: 0006-3592
    Keywords: Phanerochaete chrysosporium ; biphenyl ; PCBs ; mineralization ; biodegradation ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The white rot fungus Phanerochaete chrysosporium is unique in its ability to totally degrade a wide variety of recalcitrant pollutants. We have investigated the degradation of biphenyl and two model chlorinated biphenyls, 2,2′,4,4′-tetrachlorobiphenyl and 2-chlorobiphenyl by suspended cultures of P. chrysosporium grown under conditions that maximize the synthesis of lignin-oxidizing enzymes. Radiolabeled biphenyl and 2′-chlorobiphenyl added to cultures at concentrations in the range 260 nM to 8.8 μM were degraded extensively to CO2 within 30 days. In addition, from 40% to 60% of the recovered radioactivity was found in water-soluble compounds. A correlation between the rate of degradation and the synthesis of ligninases or Mn-dependent peroxidases could not be observed, indicating that yet unknown enzymatic system may be resonsible for the initial oxidation of PCBs. The more heavily chlorinated PCB congener, 2,2′,4,4′-tetrachlorobiphenyl was converted to CO2 less readily; approximately 9% and 0.9% mineralization was observed in cultures incubated with 40 nM and 5.3 μM, respectively. Overall, our results indicate that P. chrysosporium is a promising organism for the treatment of wastes contaminatd with lightly and moderately chlorinated PCBs. © 1992 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260401114
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  • 65
    Electronic Resource
    Electronic Resource
    Effect of adsorbents on degradation of toxic organic compounds by coimmobilized systems (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 39 (1992), S. 619-628 
    Details
    ISSN: 0006-3592
    Keywords: biodegradation ; pentachlorophenol ; coimmobilization ; mathematical modeling ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The use of coimmobilized systems for treatment of toxic organic compounds has been proposed. The proposed approach combines the use of adsorbents and laboratory identified microorganisms immobilized in a protective permeable barrier to achieve a greater degree of control over the remediation process. This study was launched to understand the effect of adsorbents and changes in adsorption on the degradation of toxic compounds by coimmobilized systems. The specific case studied involved the degradation of pentachlorophenol (PCP) by Arthrobacter (ATCC 33790) coimmobilized with powdered activated carbon within calcium alginate capsules.The design parameters studied included adsorbent content and type as well as the effect of solution pH and surfactant concentration on adsorption and biodegradation. It was found that the equilibrium adsorption behavior of PCP was strongly influenced by solution pH and surfactant concentration. A mathematical model was developed that combined the physical processes of mass transfer and adsorption with biological degradation of PCP. The model was used to predict the effect of various parameters on the degradation of PCP. Based on model predictions, the degradation of PCP. Based on model predictions, the degradation of PCP was strongly dependent on variations in adsorbent capacity and affinity for this contaminant.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260390606
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  • 66
    Electronic Resource
    Electronic Resource
    Methanogenic degradation kinetics of phenolic compounds in aquifer-derived microcosms (1991)
    Springer
    Biodegradation 2 (1991), S. 211-221 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; creosote ; ground water ; methane bacteria ; Monod kinetics ; phenols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In this segment of a larger multidisciplinary study of the movement and fate of creosote derived compounds in a sand-and-gravel aquifer, we present evidence that the methanogenic degradation of the major biodegradable phenolic compounds and concomitant microbial growth in batch microcosms derived from contaminated aquifer material can be described using Monod kinetics. Substrate depletion and bacterial growth curves were fitted to the Monod equations using nonlinear regression analysis. The method of Marquardt was used for the determination of parameter values that best fit the experimental data by minimizing the residual sum of squares. The Monod kinetic constants (μ max , K s, Y, and k d) that describe phenol, 2-, 3-, and 4-methylphenol degradation and concomitant microbial growth were determined under conditions that were substantially different from those previously reported for microcosms cultured from sewage sludge. The K s values obtained in this study are approximately two orders of magnitude lower than values obtained for the anaerobic degradation of phenol in digesting sewage sludge, indicating that the aquifer microorganisms have developed enzyme systems that are adapted to low nutrient conditions. The values for k d are much less than μ max, and can be neglected in the microcosms. The extremely low Y values, approximately 3 orders of magnitude lower than for the sewage sludge derived cultures, and the very low numbers of microorganisms in the aquifer derived microcosms suggest that these organisms use some unique strategies to survive in the subsurface environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114553
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    Electronic Resource
    Aerobic microbial metabolism of some alkylthiophenes found in petroleum (1991)
    Springer
    Biodegradation 2 (1991), S. 223-236 
    Details
    ISSN: 1572-9729
    Keywords: aerobic ; alkylthiophenes ; bacteria ; biodegradation ; isoprenoidal thiophenes ; petroleum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Six alkylthiophenes, 2-hexadecyl-5-methylthiophene (I), 2-methyl-5-tridecylthiophene (II) and 2-butyl-5-tridecylthiophene (III), 2-(3,7-dimethyloctyl)-5-methylthiophene (IV), 2-methyl-5-(3,7,11,15-tetramethyl-hexadecyl)thiophene (V) and 2-ethyl-5-(3,7,11,15-tetramethylhexadecyl)thiophene (VI) were synthesized and used as substrates in biodegradation studies. The products of their aerobic metabolism by pure bacterial cultures were identified. In most cases, the long alkyl chains of these thiophenes were preferentially attacked and in pure cultures of alkane-degrading bacteria, the major metabolites that accumulated in the medium were 5-methyl-2-thiopheneacetic acid from (I), 5-methyl-2-thiophenecarboxylic acid from (II) and occasionally from (V), 5-butyl-2-thiophenecarboxylic acid from (III) and 5-ethyl-2-thiopheneacetic acid from (VI). These transformations are consistent with the metabolism of the alkyl side chains via the beta-oxidation pathway. In contrast, 5-(3,7-dimethyloctyl)-2-thiophenecarboxylic acid was produced from (IV). Because it was available in greatest supply, (I) was studied most thoroughly. It supported growth of the six n-alkanedegrading bacteria tested and (I) was degraded more quickly than pristance but not as quickly as n-hexadecance in mixtures of these three compounds. In the presence of Prudhoe Bay crude oil and a mixed culture of petroleum-degrading bacteria, the acid metabolites from (I), (II) and (III) underwent further biotransformations to products that were not detected by the analytical methods used. The addition of n-hexadecane to the mixed culture of petroleum-degrading bacteria also enhanced the further biotransformations of the metabolites from (I).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114554
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  • 68
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    Electronic Resource
    Dynamic response of naphthalene biodegradation in a continuous flow soil slurry reactor (1991)
    Springer
    Biodegradation 2 (1991), S. 81-91 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; dynamics ; naphthalene ; dynamic response ; frequency response ; soils ; reactors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Periodic perturbations were used to evaluate the system stability and robustness of naphthalene biodegradation in a continuous flow stirred tank reactor (CSTR) containing a soil slurry. The experimental design involved perturbing the test system using a sinusoidal input either of naphthalene or non-naphthalene organic carbon at different frequencies during steady state operation of the reactors. The response of the test system was determined by using time series off-gas analysis for naphthalene liquid phase concentration and degradation, total viable cell counts, and gene probe analysis of naphthalene degradative genotype, and by batch mineralization assays. Naphthalene biodegradation rates were very high throughout the experimental run (95 to 〉99% removed) resulting in very low or undetectable levels of naphthalene in the off-gas and reactor effluent. Attempts to reduce the rate of naphthalene biotransformation by either reducing the reactor temperature from 20°C to 10°C or the dissolved oxygen level (〉1 mg/L) were unsuccessful. Significant naphthalene biodegradation was observed at 4°C. While variable, the microbial community as measured by population densities was not significantly affected by temperature changes. In terms of naphthalene biotransformation, the system was able to adapt readily to all perturbations in the reactor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114598
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    Cell-ingrowth in a silicone plombe (1991)
    Springer
    Documenta ophthalmologica 78 (1991), S. 307-315 
    Details
    ISSN: 1573-2622
    Keywords: SEM-TEM ; biodegradation ; silicone plombe ; cell ingrowth ; sclera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A male patient (42 years) who had been treated for retinal detachment by the implantation of a silicone plombe into the sclera, returned to the clinic 8 years after implantation because of inflammation of the tissue and partial protrusion from the sclera. After removal of the plombe this was processed for TEM and SEM and examination of the plombe material after 8 years in situ could be carried out in order to get information about the cell-biomaterial interface. A large proportion of the silicone pores was filled with cellular material, including macrophages, giant cells and erythrocytes thus indicating a foreign body granuloma. The external surface of the pores showed a granular osmiophilic dense amorphous layer including extracellular debris. Engulfing of silicone particles by macrophages and the evidence of long-term tissue response suggest partial biodegradation of the silicone and certainly not complete inertness as was formerly claimed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00165694
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  • 70
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    Selection and isolation of bacteria capable of degrading dinoseb (2-sec-buty-4,6-dinitrophenol) (1991)
    Springer
    Biodegradation 2 (1991), S. 1-13 
    Details
    ISSN: 1572-9729
    Keywords: anaerobic ; biodegradation ; dinitrotoluenes ; dinoseb ; nitrophenols ; 2-sec-butyl-4,6-dinitrophenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Dinoseb (2-sec-butyl-4,6-dinitrophenol) has been a widely used herbicide that persists in some contaminated soils, and has been found in groundwaters, causing health and environmental hazards. Persistence in some soils may stem from a lack of dinoseb-degrading organisms. We established a chemostat environment that was strongly selective for aerobic (liquid phase) and anaerobic (sediment phase) bacteria able to degrade dinoseb. The chemostat yielded five taxonomically diverse aerobic isolates that could transform dinoseb to reduced products under microaerophilic or denitrifying conditions, but these organisms were unable to degrade the entire dinoseb molecule, and the transformed products formed multimeric material. The chemostat also yielded an anaerobic consortium of bacteria that could completely degrade dinoseb to acetate and CO2 when the Eh of the medium was less than-200 mV. The consortium contained at least three morphologically different bacterial species. HPLC analysis indicated that dinoseb was degraded sequentially via several as yet unidentified products. Degradation of these intermediates was inhibited by addition of bromoethane sulfonic acid. GC-MS analysis of metabolites in culture medium suggested that regiospecific attacks occurred non-sequentially on both the nitro groups and the side-chain of dinoseb. The consortium was also able to degrade 4,6-dinitro-o-cresol, 3,5-dinitrobenzoic acid, 2,4-dinitrotoluene, and 2,6-dinitrotoluene via a similar series of intermediate products. The consortium was not able to degrade 2,4-dinitrophenol. To our knowledge, this is the first report of strictly anaerobic biodegradation of an aromatic compound containing a multicarbon, saturated hydrocarbon side chain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00122420
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  • 71
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    Bacterial degradation of 3-chloroacrylic acid and the characterization of cis- and trans-specific dehalogenases (1991)
    Springer
    Biodegradation 2 (1991), S. 139-150 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; 3-chloroacrylic acid ; dehalogenase ; dehalogenation ; hydratase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A coryneform bacterium that is able to utilize cis- and trans-3-chloroacrylic acid as sole carbon source for growth was isolated from freshwater sediment. The organism was found to produce two inducible dehalogenases, one specific for the cis- and the other for trans-3-chloroacrylic acid. Both dehalogenases were purified to homogeneity from cells induced for dehalogenase synthesis with 3-chlorocrotonic acid. The enzymes produced muconic acid semialdehyde (3-oxopropionic acid) from their respective 3-chloroacrylic acid substrate. No other substrates were found. The cis-3-chloroacrylic acid dehalogenase consisted of two polypeptide chains of a molecular weight 16.2 kDa. Trans-3-chloroacrylic acid dehalogenase was a protein with subunits of 7.4 and 8.7 kDa. The subunit and amino acid compositions and the N-terminal amino acid sequences of the enzymes indicate that they are not closely related.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00124488
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  • 72
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    Growth and survival of Pseudomonas cepacia DBO1(pRO101) in soil amended with 2,4-dichlorophenoxyacetic acid (1991)
    Springer
    Biodegradation 2 (1991), S. 245-252 
    Details
    ISSN: 1572-9729
    Keywords: 2,4-dichlorophenoxyacetic acid ; bacterial growth ; biodegradation ; Pseudomonas cepacia ; soil ; survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The 2,4-dichlorophenoxyacetic acid (2,4-D) degrading pseudomonad, Pseudomonas cepacia DBO1(pRO101), was inoculated at approximately 107 CFU/g into sterile and non-sterile soil amended with 0, 5 or 500 ppm 2,4-D and the survival of the strain was studied for a period of 44 days. In general, the strain survived best in sterile soil. When the sterile soil was amended with 2,4-D, the strain survived at a significantly higher level than in non-amended sterile soil. In non-sterile soil either non-amended or amended with 5 ppm 2,4-D the strain died out, whereas with 500 ppm 2,4-D the strain only declined one order of magnitude through the 44 days. The influence of 0,0.06, 12 and 600 ppm 2,4-D on short-term (48 h) survival of P. cepacia DBO1(pRO101) inoculated to a level of 6×104, 6×106 or 1×108 CFU/g soil was studied in non-sterile soil. Both inoculum level and 2,4-D concentration were found to have a positive influence on numbers of P. cepacia DBO1(pRO101). At 600 ppm 2,4-D growth was significant irrespective of the inoculation level, and at 12 ppm growth was stimulated at the two lowest inocula levels. P. cepacia DBO1(pRO101) was able to survive for 15 months in sterile buffers kept at room temperature. During this starvation, cells shrunk to about one third the volume of exponentially growing cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114556
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  • 73
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    Mineralization of 2,4-dichlorophenoxyacetic acid (2,4-D) in soil inoculated with Pseudomonas cepacia DBO1(pRO101), Alcaligenes eutrophus AEO106(pRO101) and Alcaligenes eutrophus JMP134(pJP4): effects of inoculation level and substrate concentration (1991)
    Springer
    Biodegradation 2 (1991), S. 253-263 
    Details
    ISSN: 1572-9729
    Keywords: 2,4-dichlorophenoxyacetic acid ; bacteria ; biodegradation ; kinetics ; kineralization ; xenobiotic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Mineralization of 2,4-dichlorophenoxyacetic acid (2,4-D) by two Alcaligenes eutrophus strains and one Pseudomonas cepacia strain containing the 2,4-D degrading plasmids pJP4 or pRO101 (=pJP4::Tn1721) was tested in 50 g (wet wt) samples of non-sterile soil. Mineralization was measured as 14C-CO2evolved during degradation of uniformly-ring-labelled 14C-2,4-D. When the strains were inoculated to a level of approximately 108 CFU/g soil, between 20 and 45% of the added 2,4-D (0.05 ppm, 10 ppm or 500 ppm) was mineralized within 72 h. Mineralization of 0.05 ppm and 10 ppm, 2,4-D by the two A. eutrophus strains was identical and rapid whereas mineralization by P. cepacia DBO1(pRO101) occurred more slowly. In contrast, mineralization of 500 ppm 2,4-D by the two A. eutrophus strains was very slow whereas mineralization by P. cepacia DBO1 was more rapid. Comparison of 2,4-D mineralization at different levels of inoculation with P. cepacia DBO1(pRO101) (6×104, 6×106 and 1×108 CFU/g soil) revealed that the maximum mineralization rate was reached earlier with the high inoculation levels than with the low level. The kinetics of mineralization were evaluated by nonlinear regression analysis using five different models. The linear or the logarithmic form of a three-half-order model were found to be the most appropriate models for describing 2,4-D mineralization in soil. In the cases in which the logarithmic form of the three-half-order model was the most appropriate model we found, in accordance with the assumptions of the model, a significant growth of the inoculated strains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114557
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  • 74
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    Biological fate of a polydisperse acrylate polymer in anaerobic sand-medium transport (1991)
    Springer
    Biodegradation 2 (1991), S. 171-179 
    Details
    ISSN: 1572-9729
    Keywords: acrylate ; adsorption ; biodegradation ; biotic fate ; contact time ; methanogenic consortium ; modeling ; polyacrylate ; polydisperse ; retardation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Soluble polyacrylate (PA), a polydisperse mixture of polyacrylate polymers, is strongly adsorbed and biodegradable. Biotic fate studies were carried out with once-through columns containing sand colonized with anaerobic biomass previously grown in a methanogenic fluidized bed. A fraction of soluble PA having a weight-average molecular weight of 16,700 and a range of molecular weight from 103 to 105 was biologically removed and mineralized to CO2. Due to its polydisperse nature, the breakthrough curve had a gradual increase to an apparent steady-state removal of approximately 60% near one day when the liquid detention time was 21 minutes. Modeling successfully explained the observed breakthrough result when the fraction was divided into components having a wide range of retardation factors (R): about 25% was strongly adsorbed (R=200 and 500), 45% was moderately adsorbed (R=50 and 100), and 30% was weakly adsorbed (R=1–10). In this study, in which active biomass already was present from utilization of a primary substrate (glucose here), equilibrium adsorption increased the time to breakthrough, which also reduced the exiting concentration by increasing the substrate contact time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00124491
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  • 75
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    Biodegradation of plastic bottles made from ‘Biopol’ in an aquatic ecosystem under in situ conditions (1991)
    Springer
    Biodegradation 2 (1991), S. 237-243 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; BIOPOL® ; PHB ; plastics ; poly(3-hydroxybutyrate)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments have been carried out in Lake Lugano, Switzerland, in order to study the biodegradation of poly(3-hydroxyalkanoates) (PHA) in an aquatic ecosystem under natural conditions. Commercially available plastic articles made from PHA, such as bottles and films, were incubated for 254 days in a water depth of 85 m. Shampoo bottles were positioned precisely on the sediment surface by the use of a small manned submarine. A set of bottles was attached to a buoy in order to incubate plastic material in diffent water depths. When incubated in the water column or on the sediment surface, a life span of five to ten years for this specific bottle type was calculated. In situ degradation rates of 10 to 20 mg/d were determined. PHA films were completely degraded when incubated in the top 20 cm of the sediment. The results clearly demonstrate that in an aquatic ecosystem (water column as well as sediment) under in situ conditions (i.e. low temperatures, seasonal variations of the oxygen concentration) plastic goods made from PHA are degraded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00114555
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  • 76
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    The biodegradation of mixtures of organic solvents by mixed and monocultures of bacteria (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 1037-1042 
    Details
    ISSN: 0006-3592
    Keywords: biodegradation ; organic solvents ; biooxidation ; bacteria ; competition interactions ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Much more information concerning the biodegradation kinetics of mixtures of common industrial chemicals, such as organic solvents, needs to be gathered before wastewater biotreatment process performance can become a matter of design. Here, the biooxidation of a solvent mixture comprizing methanol, acetone, isopropanol, and methylene chloride is examined. The fact that the enrichment culture obtained comprized only two solvent-utilizing strains, together with only minor percentages of nonsolvent utilizing satellite strains, was contrary to the theory of microbial competition. In addition, the complex relationship between the two solvent-utilizing strains indicates that further work is necessary on the pathways involved in isopropanol and acetone biooxidation and on the effects of operating conditions on the fluxes along such pathways.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260371108
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  • 77
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    Use of coimmobilized biological systems to degrade toxic organic compounds (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 273-279 
    Details
    ISSN: 0006-3592
    Keywords: coimmobilization ; Phanerochaete chrysosporium ; pentachlorophenol ; biodegradation ; adsorption ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The concept of coimmobilizing cell mass (and/or enzyme) and adsorbent in a hydrogel matrix for biodegradation of toxic organic chemicals was introduced. Under defined experimental conditions, the coimmobilized system using activated carbon and Phanerochaete chrysosporium was compared with nonimmobilized systems for the degradation of pentachlorophenol (PCP). It was demonstrated that the coimmobilized system degraded PCP more effectively than the nonimmobilized system. A solid substrate included in the coimmobilized system could support the biodegradation. Isolation of the degrading agents from a model interrupting microorganism by the coimmobilized capsule membrane reduced the interference on the biodegradation. In simulated contaminated soil extract and sand, the coimmobilized system also exhibited higher degradative ability and stability than the nonimmobilized systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260380309
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  • 78
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    The Swedish final repository and the possible risk of interactions by microbial activities (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 792-794 
    Details
    ISSN: 1420-9071
    Keywords: Bitumen ; biodegradation ; gas production ; radioactive waste
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The final Swedish repository for low- and intermediate-level nuclear waste is described, and some of the possible problems caused by microbial activity during storage are discussed. Microbial degradation of bitumen constitutes one of the greatest risks in the silo part of a repository. The production of carbon dioxide due to both aerobic and anaerobic processes might lead to a decrease in the pH of the water, inducing corrosion of the metal construction and storage containers, with large amounts of hydrogen gas being produced. A risk assessment for the repository must thus take into account the various activities of microbes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01935526
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  • 79
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    Enhanced degradation of iprodione in soil after repeated treatments for controlling Sclerotinia minor (1990)
    Springer
    Plant and soil 127 (1990), S. 140-142 
    Details
    ISSN: 1573-5036
    Keywords: biodegradation ; 3,5-dichloroaniline ; fungicide ; iprodione ; lettuce ; Sclerotinia minor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Poor field control of lettuce collar rot by iprodione was observed in southern France and was attributed to enhanced biodegradation of the fungicide. Enhanced biodegradation was obtained in vitro after repeated applications of iprodione to non-degrading soils. Normal soils became biodegrading after mixing with degrading soils (3 vol./1 vol.). Activity of the responsible microflora seemed dependent on soil physico-chemical characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010847
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  • 80
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    Physiology of microbial degradation of chitin and chitosan (1990)
    Springer
    Biodegradation 1 (1990), S. 177-190 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; chitin ; chitin deactylase ; chitinase ; chitosan ; chitosanase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Chitin is produced in enormous quantities in the biosphere, chiefly as the major structural component of most fungi and invertebrates. Its degradation is chiefly by bacteria and fungi, by chitinolysis via chitinases, but also via deacetylation to chitosan, which is hydrolysed by chitosanases. Chitinases and chitosanases have a range of roles in the organisms producing them: autolytic, morphogenetic or nutritional. There are increasing examples of their roles in pathogenesis and symbiosis. A range of chitinase genes have been cloned, and the potential use for genetically manipulated organisms over-producing chitinases is being investigated. Chitinases also have a range of uses in processing chitinous material and producing defined oligosaccharides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00058835
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  • 81
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    Physiology of aliphatic hydrocarbon-degrading microorganisms (1990)
    Springer
    Biodegradation 1 (1990), S. 79-92 
    Details
    ISSN: 1572-9729
    Keywords: aliphatic hydrocarbons ; alkanes ; alkenes ; biodegradation ; metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper reviews aspects of the physiology and biochemistry of the microbial biodegradation of alkanes larger than methane, alkenes and alkynes with particular emphasis upon recent developments. Subject areas discussed include: substrate uptake; metabolic pathways for alkenes and straight and branched-chain alkanes; the genetics and regulation of pathways; co-oxidation of aliphatic hydrocarbons; the potential for anaerobic aliphatic hydrocarbon degradation; the potential deployment of aliphatic hydrocarbon-degrading microorganisms in biotechnology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00058828
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  • 82
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    Transformation of metolachlor in soil inoculated with a Streptomyces sp. (1990)
    Springer
    Biodegradation 1 (1990), S. 9-17 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; decontamination of soil ; detoxication of pesticides ; metolachlor ; soil inoculation ; Streptomyces
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Microbial detoxication of pesticides may offer a promising alternative to existing physical-chemical treatment methods. We investigated a strain of Streptomyces sp. which can transform metolachlor in a liquid medium for its ability to decontaminate herbicide-treated soil. A cell suspension of Streptomyces sp. was added to a silt loam soil (Hagerstown, pH 6.1) which was amended with 10 μg of metolachlor containing 5 nCi ring-UL-14C metolachlor per gram of soil, and the mixture was incubated at 28°C. Inoculation of the sterile soil resulted in the rapid transformation of metolachlor. Analyses of one-week-old samples indicated that approximately 70% of the added radioactivity was recovered in the ethyl acetate and water fractions as products from the inoculated reaction mixture, whereas in the uninoculated control less than 8% of the 14C was found as products and about 80% was recovered in the form of unchanged metolachlor. In native soil, however, the rate of metolachlor disappearance was not enhanced by Streptomyces inoculation. In inoculated sterile soil the yields of products were affected by inoculum size, inoculation temperature and substrate concentration, but these variables had no effect on product formation in the inoculated native soil. Addition of Na2CO3 (200 μg/g soil) into native soil significantly promoted growth of Streptomyces due to the higher pH (7.8) and also stimulated transformation of metolachlor by 30%. Our results suggest that proliferation of the inoculated organisms under favorable conditions is essential for their function as metolachlor degraders in native soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00117047
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  • 83
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    Isolation and growth of a bacterium able to degrade nitrilotriacetic acid under denitrifying conditions (1990)
    Springer
    Biodegradation 1 (1990), S. 31-41 
    Details
    ISSN: 1572-9729
    Keywords: biodegradation ; denitrification ; isolation of NTA-degrading bacterium ; nitrilotriacetic acid (NTA) ; taxonomy ; wastewater treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A Gram-negative bacterium was isolated from river sediment which was able to grow with nitrilotriacetic acid as a combined carbon, nitrogen and energy source in the absence of molecular oxygen using nitrate as the terminal electron acceptor. Batch growth parameters and mass balances are reported for growth under both aerobic and denitrifying conditions. The strain was characterized with respect to its substrate spectrum and other physiological properties. This denitrifying isolate is serologically unrelated to the comprehensively described Gram-negative obligately aerobic NTA-degrading bacteria all of which belong to the α-subclass of Proteobacteria. Chemotaxonomic characterization, which revealed the presence of spermidine as the main polyamine and ubiquinone Q-8, excludes the new isolate from the phylogenetically redefined genus Pseudomonas and indicates a possible location within the γ-subclass of Proteobacteria close to, but separate from the genus Xanthomonas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00117049
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  • 84
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    Phosphonate utilization by bacteria in the presence of alternative phosphorus sources (1990)
    Springer
    Biodegradation 1 (1990), S. 43-53 
    Details
    ISSN: 1572-9729
    Keywords: phosphonates ; methylphosphonate ; p-nitrophenylphosphate ; biodegradation ; chemostat cultures ; phosphorus deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Batch and continuous culture experiments were carried out to investigate the effect of orthophosphate and p-nitrophenylphosphate on the utilization of various phosphonates as a P source by bacteria. Detailed tests with methylphosphonate as a model phosphonate and the phosphonate-degrading Pseudomonas paucimobilis strain MMM101a revealed that, in contrast with the majority of literature data, the phosphates did not suppress phosphonate utilization. Under conditions of P stress, strain MMM101a simultaneously took up both P-sources, with a preference for the phosphate-P. Study of the kinetic parameters for strain MMM101a, growing on the different P sources revealed similar, rather low, maximum growth rates (ca. 0.15 h-1). However, the affinity for orthophosphate (Ks: 0.17 μM), was more than two orders of magnitude higher than for methylphosphonate (Ks: 66 μM), which might account for the preferential uptake of orthophosphate. Cellular phosphorus yields in continuous cultures varied considerably with the conditions applied. The results suggest that phosphonate degradation can occur also in environments with substantial backgrounds of phosphate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00117050
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  • 85
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    Biological decomposition of dichloromethane from a chemical process effluent (1990)
    Springer
    Biodegradation 1 (1990), S. 221-228 
    Details
    ISSN: 1572-9729
    Keywords: dichloromethane ; biodegradation ; chlorinated aliphatics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The application of specialized microorganisms to treat dichloromethane (DM) containing process effluents was studied. An aerobic fluidized bed reactor with a working volume of 801 filled with sand particles as carriers for the bacteria was used. Oxygen was introduced into the recycle stream by an injector device. DM was monitored semi-continuously. A processor controlled the feed volume according to the DM effluent concentration. Mineralization rates of 12 kg DM/mbioreactor 3 · d were reached within about three weeks using synthetic wastewater containing 2000 mg/l DM as single carbon compound. DM from process water of a pharmaceutical plant was reduced from about 2000 mg/l in the feed to below 1 mg/l in the effluent at volumetric loading rates of 3 to 4 kg DM/mbioreactor 3 · d. Degradation of wastewater components like acetone and isopropanol were favoured, thus making the process less attractive for waste streams containing high amounts of DOC other than of DM. DM concentrations of up to 1000 mg/l were tolerated by the immobilized microorganisms and did not influence their DM degradation capacity. The ability to mineralize DM was lost when no DM was fed to the reactor for 10 days.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00119759
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