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  • 1980-1984  (404)
  • 1983  (404)
  • Biochemistry and Biotechnology  (404)
  • Nuclear reactions
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1581-1596 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A process train consisting of the following sequence of unit processes, a berl-saddle-packed anaerobic filter, an expanded bed, granular activated carbon anaerobic filter, and an activated sludge nitrification system was evaluated for the treatment of a synthetically prepared coal gasification wastewater. The first-stage anaerobic filter resulted in very little removal of organic matter and no methane production. Excellent reduction in organic matter occurred in the granular activated carbon anaerobic filter. The removal mechanism was initially adsorptive and near the end of the study, removal of organic matter was primarily through conversion to methane gas. It is felt that the success of the activated carbon anaerobic filter was due to the ability of the activated carbon to sequester some components of the wastewater that were toxic to the mixed culture of anaerobic microorganisms. The activated sludge nitrification system resulted in complete ammonia oxidation and was very efficient in final effluent polishing.
    Additional Material: 8 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1597-1612 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Evaporative loss of ethanol during batch alcoholic fermentation has been modelled, employing modern concepts of kinetics and stoichiometry and the best available phase equilibrium thermodynamic data. Theoretical results demonstrate that loss is proportional to the second power of the sugar concentration utilized and that the logarithm of loss is proportional to reciprocal absolute temperature. Good agreement is demonstrated among the theory, the numerical model, and the literature results. A master correlation for predicting ethanol loss is presented.
    Additional Material: 3 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1613-1623 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method of adapting a kinetic model based on steady-state chemostat data to predict the transient performance of a chemostat culture is presented. The proposal provides for a time delay which can be considered equivalent to a period of reduced activity of the organism subsequent to the introduction of a step change in operating conditions. The adapted kinetic model gives substantially better performance in predicting the transient response of an experimental system than the unmodified kinetic model.
    Additional Material: 8 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1653-1654 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1789-1800 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method suitable for large-scale isolation of β-galactosidase from a suspension of disintegrated E. coli cells has been developed. In an aqueous two-phase system consiting of PEG 6000 and potassium phosphate, all cell debris and the major part of the proteins and nucleic acids were partitioned to the denser salt phase. Seventy-five percent of the β-galactosidase was recovered in the lighter PEG phase, giving a purification ratio of about 12.
    Additional Material: 3 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1781-1788 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A high phosphate accumulating bacterium, Arthrobacter globiformis PAB-6, was grown in a chemostat under glucose-limitation. Two different growth patterns at steady state with various dilution rates were obtained. In one case, cells having a coccus shape tended to washout at a low dilution rate, 0.2 (h-1). In another, cells with a rod shape grew faster and gave a good steady-state growth at a dilution rate of 0.4. Such a close relationship between growth rate and cell morphology was found both in continuous and batch cultures. The amount of phosphate uptake per cell mass was almost constant irrespective of the dilution rate, but the rate of the uptake was maximum at about the dilution rate of 0.4. A clone of PAB-6 was isolated from the continuous culture with high dilution rate and had maximum specific growth rate of 0.7 in a simple glucosesalt medium.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1801-1816 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Oocystis sp., a unicellular green alga, contained two glutamate dehydrogenase isoenzymes: one was specific for NADH and the other for NADPH. Activity staining after gel electrophoresis indicated that one component in NADH-GDH was not specific for the cofactor and three components in NADPH-GDH. The optimal concentration of substrate, purification procedure and kinetic properties of both glutamate dehydrogenase (GDH) enzymes in vitro are presented. The kinetics of growth, nutrient removal and enzyme activities for Oocystis growing in wastewater showed that ammonia was preferentially utilized over nitrate and the medium was depleted before the maximum population was obtained in indoor culture. There was a sharp increase in NADPH-GDH activity following the exhaustion of ammonia from the medium but NADH-GDH activity remained unchanged. The NADPH-GDH activity at the outset increased exponentially with time in greenhouse culture but then decreased sharply accompained by a rapid increase in biomass and nitrite concentration. The Km values for ammonia in this algal GDH was high, while glutamate synthase activity was not detected; this suggests that Oocystis may adapt to conditions of ammonia limitation by producing large quantities of NADPH-GDH instead of using glutamate synthase pathway.
    Additional Material: 10 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1829-1839 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Kinetics of the degradation of olive oil by an acclimated activated sludge were studied. Kinetic constants for the lipid removal from the mixed liquor and for that from the supernatant and for the hydrolysis step were evaluated using Michelis-Menten equations. The maximum specific reactions rates (vmax) and the saturation constants (Km) were vmax = 1.20 mg lipid mg-1 MLVSS day-1 and Km = 1290 mg/L for lipid removal from the mixed liquor; vmax = 1.54 mg lipid mg-1 MLVSS day-1 and Km = 801 mg/L for that from the supernatant; vmax = 1.57 mg olive oil mg-1 MLVSS day-1 and Km = 1750 mg/L for the hydrolysis of olive oil (where MLVSS refers to mixed liquor volatile suspended solids). The adsorption of olive oil by the activated sludge contributed to the lipid removal from the supernatant. The specific rate of this adsorption was also estimated. The hydrolysis, rather than the oxidation of free fatty acids, was the rate limiting step in the degradation of olive oil when the concentration of olive oil was lower than about 800 mg/L.
    Additional Material: 8 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2359-2370 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A rotating drum fermentor designed for plant cell suspension cultures was constructed and tested. The oxygen transfer coefficient (kLa) and power requirements in the fermentor were determined with the water system under various conditions and the relationship between them in the fermentor was clarified. Also, the relationship between kLa and the apparent viscosity in the fermentor was investigated in the cell suspension system. The rotating drum fermentor was found to be superior to the mechanically agitated fermentor in the capacity of oxygen supply under high viscosity and low hydrodynamic stress conditions. This finding was also confirmed by the experiments with plant cell suspension cultures.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2371-2393 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A process for producing a higher-fructose syrup containing more than 50% fructose was developed that involves a new system combining selective adsorption of fructose and an immobilized glucose isomerase reaction. Continuous countercurrent contact of the liquid stream with the solid adsorbent is simulated by advancing adsorption columns against the fixed inlets and outlet of liquid streams without actual movement of the solid adsorbent, while the immobilized enzyme reactors are stationary. Two mathematical models, an intermittent moving-bed and a continuous moving-bed model, are presented for calculation the concentration profiles of glucose and fructose in the system. The validity of the models is experimentally confirmed, and a criterion for good production in the system is presented. This system requires less desorbent than a process using a fixed-bed adsorber and a simulated moving-bed process to produce the syrup with 45-65% fructose content, the level desired in food manufacture.
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  • 11
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2843-2853 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Axenic cultures of Rhodopseudomonas capsulata. Rhodospirillum rubrum, and Rhodomicrobium vannielii grown with glutamate as the nitrogen source converted lactate, acetate, and butyrate to H2 and CO2. Conversion rates ranged from 100 to 926 mL H2 Lr-1 day-1 (where Lr is the reactor contents), and efficiencies varied from 23 to 100% When grown with N2, conversion rates up to 760 mL H2 Lr-1 day-1 and efficiencies up to 100%were achieved. Upon aging, cultures appear to rapidly increase in hydrogen uptake activity and furthermore decrease in nitrogenase activity, both factors leading to a slowdown of hydrogen production. This was particularly the case for diazotrophically grown photobacteria.
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  • 12
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2803-2841 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microbial kinetics and energetics are discussed in connection with the formulation of unstructured growth models. The development of microbial energetics and the use of macroscopic methods in the study of microbial growth are briefly evaluated. The general approach to the modelling of microbial growth has been critically discussed and a strategy for the formulation of unstructured models is presented. A simple unstructured model based on Monod kinetics and the linear relation for substrate consumption is evaluated with reference to extensive experimental and simulation data obtained in batch, fed-batch, and continuous cultivation modes. Choice for a kinetic expression is discussed and has been shown not to be critical in most situations. It is shown that during growth in batch mode, the behavior of the system is rigidly fixed by the kinetic parameter: the maximum specific growth rate. The energetic parameters have minimal influence. In continuous cultivation the behavior is fixed by the energetic parameters: the maximum yield and the coefficient of maintenance. Implications of these observations have also been discussed. The linear relation for substrate consumption is tested with continuous culture data. It is shown that significant deviations at low growth rates cannot be fully accounted by the loss of viability. The situations where unstructured models will be adequate or not for system description, are evaluated and checked experimentally. Influence of an environmental factor, the temperature, on the unstructured model parameters is also quantitatively described. It is concluded that the art of unstructured model building has already reached its maturity and that now much effort should be channelled into the development and verification of structured models.
    Additional Material: 22 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2855-2864 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The cell-associated β-glucosidase activity of Thermomonospora fusca, strain YX, showed both PNPGase and cellobiase activities. The cellobiase activity was found by HPLC assay to have very low product inhibition, whereas the PNPGase activity was more significantly inhibited. Of the various sugars and sugar analogs tested for inhibition of the PNPGase activity, gluconolactone had the greatest effect. The low product inhibition of the cellobiase activity was further demonstrated by the production of glucose syrups to 20% concentration from both cellobiose and swollen cellulose (Avicel). This characteristic is of practical importance in the development of a commercial process for the production of glucose syrups from cellulose. Growth experiments gave further evidence for the probability of separate enzymes for the PNPGase and cellobiase activities.
    Additional Material: 6 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2865-2872 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The saccharification of cellulosic substrates by cellulase from Thermomonospora fusca, strain YX, was influenced by the presence of various substances. Cellobiose was strongly inhibitory, reducing the activity against swollen cellulose to 25% at 5% concentration. Glucose had much less effect, reducing activity to 40% at 20% concentration. Ethanol was found to be only slightly inhibitory to the cellulase, reducing activity by about 15% at 6% concentration, but much more inhibitory to the cell-bound β-glucosidase activity. Of the numerous metal ions examined, Ca2+ and Co2+ at 0.1mM-1.0mM concentration were found to be slightly activating under assay conditions, while 1.0mM Pb2+ and Hg2+ were the most inhibitory ions. The implications of these results for the design of commercial processes for ethanol production from cellulose are discussed.
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  • 15
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 16
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1-2 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 17
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 3-17 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model was developed for a percolation reactor in connection with consecutive first-order reactions. The model was designed to simulated acid-catalyzed cellulose or hemicellulose hydrolysis. The modeling process resulted in an analytically derived reactor equation, including mass-transfer effects, which was found to be useful in process desing and reactor optimization. The modedl was verified by experimental data obtained from hemicellulose hydrolysis.
    Additional Material: 9 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 19-32 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pentosan hydrolysis at low aqueous liquid-to-biomass ratios (2.5-15 mL/g) with sulfuric acid as the catalyst is studied in the temperature range of 125-155°C. To facilitate heat transfer and mixing a second insoluble oil is added to the reaction mixture. It is found that even at high slurry concentrations, the reaction is the rate-controlling step. In addition, such systems give higher pentosan yields compared with dilute slurry systems. This is explained using the concept of acid loading which is defined as the acid present per unit mass of biomass.
    Additional Material: 8 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 53-65 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new type of reactor, an attrition bioreactor, was tested to achieve a higher rate and extent of enzymatic saccharification of cellulose than is possible with conventional methods. The reactor consisted of a jacketted stainless-steel vessel with shaft, stirrer, and milling media, which combined the effect of the mechanical action of wet milling with cellulose hydrolysis. The substrates tested were newsprint and white-pine heartwood. The performance of the reactor was excellent. The extent and rate of enzymatic hydrolysis could be markedly improved over other methods. The power consumption of the attrition bioreactor was also measured. The cellulase enzyme deactivation during attrition milling was not significant.
    Additional Material: 10 Ill.
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  • 20
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2945-2956 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using two species of yeast and one of bacterium, evidence has ben obtained which indicates that the microbial uptake of solid alkane powders occurs primarily through a substrate solubilization mechanism. EDTA, a strong inhibitor of hydrocarbon solubilization by the cells, inhibited the growth of these organisms on alkane powder; the inhibition could be removed vai a supply of artificially solubilized alkane. One of the yeast strians, which was a mutant incapable of growing on solid alkane powder and liquid alkane, could grow very well on artifically solubilized alkanes. It was demonstrated that the solid alkane solubilization rate during microbial growth could satisfactorily account for the maximal alkane uptake rate actully observed during growth. The specificity of solubilization for the solid alkane used as the growth substrate was demonstrated.
    Additional Material: 5 Ill.
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  • 21
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    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2929-2943 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The mode of uptake of sterols, which are nearly insoluble in water by an Arthrobacter species, was studied on the basis of substrate transfer via the aqueous phase (solubilization/pseudosolubilization) and through direct contact with sterol particles. Growth of the organism, on stero powder was predominantly in nonlogarithmic in character, indicating a possible limitation of substrate transfer. Soluble sterol was shown to be the preferential form of the substrate for assimilation by the organism. Evidence was obtained for increased solubilizition of β-sitosterol and cholesterol during microbial growth on these substrates. But the rate of solubilization of β-sitosterol (3.06 mg L-1 h-1) was too inadequate to account for the observed substrate uptake rare (107 mg L-1 h-1) during growth. A cholesterol solubilization rate of 44 mg L-1 h-1 could, however, account to an appreciable extent for the observed cholesterol uptake rate of 140 mg L-1 h-1 during growth. Increasing attachement of cells to sterol particles during growth was observed by microscopic examination, indicating that growth may take place over the surface of sterol particles. By using the synthetic surfactant HYOXYD AAO (alkyl aryl polyglycol ether), which prevented attachment of cells to sterol particles without affecting the metabolic integrity of the cells, it was shown that growth indeed took place predominantly on the surface of the sterol particles. Increased generation of finer particles of sterol, which provides increased substrate surface area during growth, was demonstrated. It was concluded that with β-sitosterol, growth takes place almost entirely by attachement, whereas with cholesterol, about 30% of the growth take place on solubilized substrate and the rest through attachament.
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  • 22
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    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2957-2967 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In this report, α-Amylase originating from Bacillus subtilis (liquefying type) was immobilized on partially imidoesterized polyacrylonitrile (PAN) by covalent bonding. For the preparation of immobilized α-amylase, which has a high activity and high stability to repeated use, the optimum conditions for the preparation reaction were investigated. The optimum conditions for the preparation reaction were quantified on the basis of the enzymatic activity, the preservation of the activity during repeated use in batch process and the protein content on the support. Further-more, enzymatic properties of immobilized α-amylase prepared at optimum conditions were compared with the native enzyme. The optimum temperature and reaction time for the imidoes-terification reaction were 30°c and 6 h, respectively, whereas those of the amidinatin reaction were 30-40°C and more than 3 h, respectively; the optimum pH range was 9-10. Immobilized α-amylase prepared at the optimum conditions was very stable against the repeated use and had more than 90% of relative to activity of the first use after the tenth procedure. The initial reaction rate of immobilized α-amylase was lower than native α-amylase, but same amount of reducing sugars were produced after the reaction passed for more than 90 min. The immobilized α-amylase was less stabel at the high temperature and the more basic media. However, after long incubation time, immobilized α-amylase was more stable than the native enzyme in exposure to heat and a storng base.
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  • 23
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2969-2980 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In a previous publication, the authors described the establishment of a working system for studing effects of factors involved in the chemical nature of a microcarrier on cell attachment, spreading, and growth. The first part of the rsearch dealt with the influence of the type and amount of the positively charged groups. In the present article, the authors will describe the effect of the introduction of hydrophobic elements onto primary amino derivatized polyacrylamide microcariers. It was found that cell attachement kinetics were gradually enhanced in parallel to a gradual increase in hydrophobicity via elongation of the hydrocarbon side-chain carrying the primary amino charged group. A threshold effect of the amount of charge required for cell attachment spreading and growth was exhibited on all the tested primary amino derivatized microcarriers. Optimum cell growth was recorded for the butylamine and hexylamine polyacrylamide microcarris. Lowre cell yields were recorded for ethylamine and octylamine derivatives. The location of the introduced hydrophobic element has a profound effect on cell propagation. Introduction of hydrophobicity onto the polymeric backbone of the microcarrier (via copolymerization of hydrophobic comonomer) lead to negative influence on cell attachement and growth yields. Out of the series of derivatized polyacrylamide microcarriers tested, it seems that the hexylamine derivative may be a potential alternative for the commonly used tertiary amine microcariers.
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  • 24
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2981-2990 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The contiuously fed batch reactor (CFBR) is proposed as an alternative technique to the traditional chemostat and batch cultures, for measuring microbial growth rates. After reviewing the pitfalls which plague the conventional growth measurement techniques, the methodology for operating the CFBR to generate specific growth-rate-versus-substrate-concentration data is detailed. This information is extracted from the transient state of the CFBR where both the biomass and substrate concentration show extrema in time. It is suggested that the CFBR can be used for measuring microbial growth rates at low rates at low substrate concentrations where the chemostat method normally encounters difficulties.
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  • 25
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 3005-3011 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Culture filtrates of CL-847 strain of Trichoderma reesei grown on different carbon sources have been compared. The highest enzyme production is obtained with Whatman C 41 cellulose: 17.9 mg/mL of soluble proteins and 13.7 units of filter paper (FP) activity. Wood pulps gave lower production values and more viscous culture media. About one-third of maximal enzyme production is obtained on lactose as the sole carbon source. Addition of 0.5% cellulosic inducer to 6% lactose media enhances enzyme production up to the following levels: 14.1 mg/mL of soluble proteins and 8.4 units of FP activity.
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  • 26
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 2991-3003 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although a shift in nutritinal conditins brings about transient unbalanced growth in normally grown Escherichia coli, a shift in temperature without changing the nutritional conditions results in immediate adaptation to the new conditions. However, when a medium contained an insufficient amount of nutrient, such as glucose, a temperature shift caused a lag time in temperature shiftup was primarily determined by the postshift temperature. These situatins were quite similar to those observed in nutrient shiftup, but a growth profile during the lag time was more distorted than that found in the nutrient shiftup. The transient unbalanced growth appeared to be caused by a difference in physiological states of bacteria, as expressed by macromolecule content per cell characterized by the pre and postshift environments, and was capable of expressing theoretically its profile and duration according to the model of Cooper and Helmstetter. On the other hand, the shiftdown in temperature in the presence of a limiting concentration of glucose caused extraordinarily long lag time, and transient cessation of cell division during that period. This response was unable to explain by the Cooper and Helmstetter model. In contrast to the temperature shiftup, the duration of lag time in the shiftdown was expresed as functions of the poshift temperature and the difference in physiological states of the pre- and postshift environments.
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  • 27
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    Biotechnology and Bioengineering 25 (1983), S. 3013-3026 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new method for the automated analysis of inorganic phosphorus using immobilized enzyme was established. The method was based on the determination of hydrogen peroxide formed by the action of pyruvate oxidase on inorganic phosphate and pyruvate. Since pyruvate oxidase required inorganic phosphate for its stability and therefore had to be kept in a buffer containing inorganic phosphate, it could hardly be used as a reagent in the form of aqueous solution for the determination of inorganic phosphorus. This difficulty was overcome by using immobilized pyruvate oxidase in column form. When the present method was applied to the determination of inorganic phosphorus in serum, it gave perfect linearity of the data up to 0.20 g inorganic phosphorus/L with satisfactory precision, reproducibility, high sensitivity, and accurate recoveries. The immobilized enzyme reactor unit showed enhanced heat stability and good operational stability for a one-month period, during which time it was used over 900 times for analyses. The enzyme column was not affected by organic phosphorus compounds. The results correlated satisfactorily with those obtained by another well-established method.
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  • 28
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    Biotechnology and Bioengineering 25 (1983), S. 173-183 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fermentation of xylose by Klebsiella pneumoniae (ATCC 8724, formerly known as Aerobacter aerogenes) carried out in our laboratory yields 2,3-butanediol as the major product. Experimental data obtained in this work cannot be explained by the model presently in the literature for the formation of 2,3-butanediol isomers from acetoin isomers. A new model is proposed with the existence of two acetoin reductases and an acetoin racemase. The two reductases were separated and their stereospecificity determined. Extension of the model of other microorganisms is discussed.
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  • 29
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of temperature (35 and 55°C) and straw-manure mixtures (90, 75, 50, and 0% straw) on methane (CH4) production were studied using laboratory-scale fermentors. Batch fermentations showed that the ultimate CH4 yield (B0) of straw-manure mixtures was directly proportional to the relative proportion and B0 of the individual components. Also, hammer or ball milling did not increase the B0 of straw. Kinetic analysis showed that fermentation stress occurred when the straw content of straw-manure mixtures was higher than 40% at 35°C, or higher than 75% at 55°C. This fermentation stress was observed to occur when the free ammonia concentration was below 10 g/m3.
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  • 30
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    Biotechnology and Bioengineering 25 (1983), S. 201-215 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Selected samples of waste microbial biomass used in industrial fermentation processes and wastewater biological treatment plants have been studied for their radium biosorption ability from aqueous solutions. Equilibrium biosorption isotherms have been used to quantify the radium uptake capacity of the various types of biomass which were also compared to two types of activated carbon. Solution pH affected the observed uptake significantly. In general, the biomass types that showed appreciable sorption capacity exhibited maximum uptake between pH 7 and 10. The uptake was reduced considerably at pH 4 and little or no uptake was observed at pH 2. Radium biosorptive uptake capacities of the order of 4.5 × 104 nCi/g, at pH 7 and at an equilibrium radium concentration of 1000 pCi/L, were determined for a mixed culture, while the biomass of Penicillium chrysogenum adsorbed 5 × 104 nCi/g radium under the same conditions. The highest uptake value for a sample of F-400 granular activated carbon was 3600 nCi/g at pH 7 and 1000 pCi/L radium concentration. The biosorptive radium uptake of microbial biomass is compared to literature values for other types of adsorbents. The most effective biomass types studied exhibited radium removals in excess of 99% of the radium in solution.
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  • 31
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    Biotechnology and Bioengineering 25 (1983), S. 225-255 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A computer-aided methodology is developed for on-line monitoring and control of cell growth in fed-batch penicillin fermentation using a semidefined medium containing low corn steep liquor concentration (5.7 g/L). Cell growth is monitored and controlled with the use of experimental correlation and carbon-balancing equatiions on a real-time basis throughout the fermentation. Through a combination of feed-forward and feedback control of sugar addition, residual glucose concentration in the broth was maintained below 1 g/L and cell-growth rate was kept at constant at preset vaiues. The accuracy and reproducibility of this technique are demonstrated. The use of real-time control of cell growth is expected to aid future investigations of this antibiotic fermentation.
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  • 32
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    Biotechnology and Bioengineering 25 (1983), S. 271-280 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The sorption characteristics of the cellulase system of Talaromyces emersonii on various cellulosic substrates were examined. Analysis of reaction mixture supernatants by electrophoresis and enzyme assay showed that all components of the cellulase system were rapidly adsorbed by cellulose and then gradually returned to the liquid phase as the hydrolysis of the substrate progressed. The extent of adsorption in the rapid phase was influenced by pH, temperature, the nature of the substrate, and its concentration.
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  • 33
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    Biotechnology and Bioengineering 25 (1983), S. 257-269 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To broaden the practicality of on-line growth monitoring and control, its application in fedbatch penicillin fermentation using high corn steep liquor (CSL) concentration (53 g/L) is demonstrated. By employing a calculation method that considers the vagaries of CSL consumption, overall and instantaneous carbon-balancing equations are successfully used to calculate, on-line, the cell concentration and instantaneous specific growth rate in the penicillin production phase. As a consequence, these equations, together with a feedback control strategy, enable the computer control of glucose feed and maintenance of the preselected production-phase growth rate with error less than 0.002 h-1.
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  • 34
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    Biotechnology and Bioengineering 25 (1983), S. 281-299 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The potential of continuous isopropanol-butanol-ethanol (IBE) fermentation by Ca-alginate-immobilized Clostridium beijerinckii cells in a continuous stirred-tank reactor is investigated. A mathematical model is presented to describe steady-state reactor performance. It appeared to be possible to use the biocatalyst particles repeatedly for successive fermentations (at least three times for a total duration of two months). Reactor productivity was 6-16 times higher than that of a batch fermentation (free cells), while the solvents yield was also increased. Measurements of substrate, product, and biomass concentrations were only partially in agreement with the model; however, a solid basis for further technological developement of the process has been laid.
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  • 35
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    Biotechnology and Bioengineering 25 (1983) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 36
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    Biotechnology and Bioengineering 25 (1983), S. 307-313 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
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  • 37
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    Biotechnology and Bioengineering 25 (1983), S. 301-306 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: We formulate a variant of the “double Monod model” which takes explicit account of endogenous metabolism. Using parameter values appropriate to carbohydrate-limited substrate, bacterial prey, and protozoan predator, we study the stability of steady states under chemostat conditions. We conclude that the predator's endogenous metabolism may have a stabilizing effect at low dilution rates.
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  • 38
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    Biotechnology and Bioengineering 25 (1983), S. 317-327 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two types of artificial membranes containing a phospholipid were prepared and their permeabilities were measured around the phase-transition temperature of the phospholipid. The permeability of the membranes to a hydrophobic solute was higher than to a hydrophilic solute, and showed an abrupt change at the phase-transition temperature of the phospholipid, similar to that in biomembranes and liposomes, caused by the fluidity change of the phospholipid at this temperature.
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  • 39
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    Biotechnology and Bioengineering 25 (1983), S. 3191-3195 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 40
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    Biotechnology and Bioengineering 25 (1983), S. 3197-3199 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Tab.
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  • 41
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    Biotechnology and Bioengineering 25 (1983), S. 3201-3206 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 42
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    Biotechnology and Bioengineering 25 (1983), S. 377-385 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A purified endocellulase from Sclerotium rolfsii and a crude cellulase preparation from Trichoderma reesei are used to illustrate several pitfalls associated with the assay of carboxymethylcellulase activity and the subsequent attainment of linear enzyme dilution curves. It is shown that the nature of both the enzymes and the substrate make the assay unsuitable for use in the calculation of enzyme recovery and purity.
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  • 43
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    Biotechnology and Bioengineering 25 (1983), S. 403-416 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simple approach was developed to determine the half-saturation coefficient for dissolved oxygen (KDO) for three bacteria by maintaining a constant oxygen concentration in continuous culture, and employing a dynamic method to obtain the specific growth rate (μ) for each species. Measurement of μ at selected dissolved oxygen concentrations (DO) resulted in a typical Monod curve for a plot of μ vs. DO. Values for KDO and μmax were obtained from the Lineweaver-Burk reciprocal plot. The bacteria studied included representative strains of three microorganisms isolated in pure culture from poorly settling activated sludge: two filamentous microorganisms, Sphaerotilus natans and a second Sphaerotilus sp., and an unidentified floc-forming microorganism. The KDO values obtained for Sphaerotilus sp., S. natans, and the floc former were 0.014, 0.033, and 0.073 mg/L, respectively. Dual species competition experiments were conducted in continuous culture under low and high DO conditions. Successful growth competition by these microorganisms under DO-limiting conditions was consistent with experimentally determined KDO values. The finding of lower KDO values for the two Sphaerotilus species, compared to the floc former, confirmed the hypothesis that these filamentous microorganisms can outgrow floc-forming microorganisms in activated sludge when DO in the aeration basin is low.
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  • 44
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    Biotechnology and Bioengineering 25 (1983), S. 387-401 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pseudomonas PG-1 cultivated on pristane produced in good amount a heat-stable polymeric substance which showed strong hydrocarbon emulsifying and solubilizing properties. The substance was isolated in crude form and was found to contain 34% protein, 16% carbohydrate, and 40% lipid. The hydrocarbon solubilizing activity of the isolate was strongly inhibited by EDTA but the chelating agent had no effect on the hydrocarbon emulsifying activity. Both activities of the isolate were strongly inhibited by chymotrypsin treatment indicating the importance of the protein moiety for its activity. Hydrocarbon solubilization by the isolate showed a certain degree of specificity to pristane in modest agitation generally used in microbial cultivation, but this specificity was lost by vigorous agitation in a Waring blender. It was proposed that in the first case, solubilization was effected by a solubilizing factor specific to pristane, whereas in the latter case, nonspecific solubilization occurred due to the action of the emulsifying factor. The rate of pristane solubilization by heat-treated culture broth under the conditions of agitation used in cultivation (rotary shaker, 120 rpm) was found to be ca. 750 mg L-1 h-1 which was much larger than the maximal pristane uptake rate of 170 mg L-1 h-1 observed during microbial growth on the substrate. It was concluded that hydrocarbon solubilization could satisfactorily account for the substrate uptake and growth.
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  • 45
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    Biotechnology and Bioengineering 25 (1983), S. 417-436 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: E. Coli was cultivated in batch and continuous operations in the presence of an antifoam agent in stirred-tank and in single- and ten-stage airlift tower reactors with an outer loop. The maximum specific growth rate, μm, the substrate yield coefficient, Yx/s, the respiratory quotient, RQ, substrate conversion, Us, the volumetric mass transfer coefficient, KLa, the specific interfacial area, a, and the specific power input, P/VL, were measured and compared. If a medium is used with a concentration of complex substrates (extracts) 2.5 times higher than that of glucose, a spectrum of C sources is available and cell regulation influences reactor performance. Both μm and YX/S, which were evaluated in batch reactors, cannot be used for continuous reactors or, when measured in stirred-tank reactors, cannot be employed for tower-loop reactors: μm is higher in the stirred-tank batch than in the tower-loop batch reactor, μm and Yx/s are higher in the continuous reactor than in the batch single-stage tower-loop reactor. The performance of the single-stage is better than that of the ten-stage reactor due to the inefficient trays employed. A reduction of the medium recirculation rate reduces OTR, Us, Pr, and YX/S and causes cell sedimentation and flocculation. The volumetric mass transfer coefficient is reduced with increasing cultivation time; the Sauter bubble diameter, ds, remains constant and does not depend on operational conditions. An increase in the medium recirculation rate reduces kLa. The specific power input, P/VL, for the single-stage tower loop is much lower with the same kLa value than for a stirred tank. The relationship kLa vs. P/VL evaluated for model media in stirred tanks, can also be used for cultivations in these reactors.
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  • 46
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    Biotechnology and Bioengineering 25 (1983), S. 437-450 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: During the cultivation of E. coli in an airlift tower-loop bioreactor, the following properties were measured: transverse profiles of Sauter bubble diameter, dS; local relative gas holdup, EG; bubble rise velocity, uBS; local mean velocity, ū turbulence intensity, u′; macrotime scale, TEL; dissipation time scale, τE; power spectrum, E(n); and energy dissipation spectrum D(n) at different distances from the aerator. The influence, distance from the aerator, absence and/or presnece of cells, and batch and/or continuous-culture operation on the behavior of the two-phase system are discussed on the basis of these properties.
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  • 47
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    Biotechnology and Bioengineering 25 (1983), S. 451-467 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The hypothesis that at least some penicillin acylases react via an acyl-enzyme intermediate was tested by kinetic investigations involving the methyl ester of cyanoacetic acid as the acyl donor, deacetyl-7-aminocephalosporanic acid as the acyl receptor, and penicillin acylase (E.C.3.5.1.11) from B. megaterium ATCC 14945 as the catalyst. The results obtained at low concentrations of the acyl receptor are in accord with the derived rate equations. Deviations observed at higher concentrations of the acyl receptor are discussed together with some practical implications of the mechanism.
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  • 48
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    Biotechnology and Bioengineering 25 (1983), S. 497-511 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model for glucose-to-ethanol fermentation at high yeast cell concentrations was developed. The feasibility of improving fermenter productivity over that of a conventional continuous-stirred-tank fermenter by using multiple stage reactors and yeast cell recycling was predicted by computer simulation. The optimum size distribution for multistage fermentors was obtained for different glucose feedstream concentrations and different glucose conversion levels. Productivity increases over a single-stage reactor ranged from 1.2-2.0 times. The use of yeast cell recycling to increase cell concentration and productivity increases of over 4.0 times that of a system without recycling.
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  • 49
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    Biotechnology and Bioengineering 25 (1983), S. 513-523 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Laboratory-scale biotreaters were used to study the effects of NH3-N and PO4-P nutrients on the activated sludge treatment of a chemical waste containing soluble calcium (1300 mg/L). Units receiving high or low levels of NH3-N and PO4-P were similar in their ability to remove organic compounds from the waste. Adaptation of sludges to low PO4-P levels (〈0.1 mg/L effluent) resulted in a marked accumulation of CaCO3 in the biosolids, whereas those receiving high PO4-P (2-4 mg/L effluent) had little CaCO3. Microscopic observations of CaCO3 containing sludges showed substantial amounts of CaCO3 crystals imbedded in the biomass. These flocs also appeared to be enriched with nonfilamentous bacterial species in contrast to flocs devoid of CaCO3 which had a floc structure of filamentous and nonfilamentous organisms. Scanning electron micrographs of flocs grown under low NH3-N showed a microbial fibrillar network of exocellular material interconnecting cells in the floc matrix. The sludges adapted to low NH3-N also produced higher amounts of extractable polysaccharide. CaCO3 containing biosolids were more dense, larger, and settled better (low SVI, high ISV) than flocs devoid of the precipitates. It is not known from our experiments whether PO4-P or some inorganic or organic polymer produced by the floc bacteria are involved in inhibiting CaCO3 precipitation in the activated sludge treatment of calcium-containing wastes.
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  • 50
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fungal α-amylase (E.C. 3.2.1.1) and glucoamylase (E.C. 3.2.1.3) were chemically attached to separate reactor modules made from Microporous Plastic Sheet (MPS). Immobilization of enzymes and subsequent chemical reactions were accomplished by pumping reactants through the sheet, i.e., perpendicular to the surface. The expressed activity of the reactor modules was ca. 800 U/g for both fungal α-amylase and glucoamylase. The kinetics and short-term effects of pH and temperature on the expressed activity of the immobilized enzymes were investigated. Using commercially available DE-42 corn syrup at 50% dissolved solids, half-lives of 2000 and 5000 h were achieved for glucoamylase and fungal α-amylase, respectively. The reactors were operated at 50°C and at pH 4.3 for glucoamylase and 5.5 for fungal α-amylase. A typical DE-62 corn syrup product was continuously produced in a two-stage reactor system by pumping the feedstock through the glycoamylase reactor and then through the fungal α-amylase reactor. Saccharide distributions at each stage were controllable to ±0.2%.
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  • 51
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    Biotechnology and Bioengineering 25 (1983), S. 559-568 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Potentiometric and amperometric measurements were made with microbial fuel cells containing E. coli or yeast as the anodic reducing agent and glucose as the oxidizable substrate. The catalytic effects of thionine and resorufin on the anode reaction were investigated. Results on the potentiometry, polarization, and coulombic output of the cells support a mediator-coupled mechanism for the transfer of electrons from the organism to the electrode in preference to a mechanism of “direct” electrochemical oxidation of glucose or its degradation products. Experiments with 14C-labeled glucose show that when a microbial fuel cell produces a current under load, exogenous glucose is metabolized to produce 14CO2. The Coulombic yields of the cells indicate a high degree of energy conversion in these systems.
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  • 52
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    Biotechnology and Bioengineering 25 (1983), S. 541-557 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Twenty-two different yeasts were screened for their ability to ferment both glucose and cellobiose. The fermentation characteristics of Candida lusitaniae (NRRL Y-5394) and C. wickerhamii (NRRL Y-2563) were selected for further study because their initial rate of ethanol production from cellobiose was faster than the other test cultures. C. lusitaniae produced 44 g/L ethanol from 90 g/L cellobiose after 5-7 days. When higher carbohydrate concentrations were employed, fermentation ceased when the ethanol concentration reached 45-60 g/L. C. lusitaniae exhibited barely detectable levels of β-glucosidase, even though the culture actively fermented cellobiose. C. wickerhamii produced ethanol from cellobiose at a rate equivalent to C. lusitaniae; however, once the ethanol concentration reached 20 g/L, fermentation ceased. Using p-nitrophenyl-β-D-glucopyranoside (pNPG) as substrate, β-glucosidase (3-5 U/mL) was detected when C. wickerhamii was grown anaerobically on glucose or cellobiose. About 35% of the β-glucosidase activity was excreted into the medium. The cell-associated activity was highest against pNPG and salicin. Approximately 100-fold less activity was detected with cellobiose as substrate. When empolying these organisms in a simultaneous saccharification-fermentation of avicel, using Trichoderma reesei cellulase as the saccharifying agent, 10-30% more ethanol was produced by the two yeasts capable of fermenting cellobiose than by the control, Saccharomyces cerevisiae.
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  • 53
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    Biotechnology and Bioengineering 25 (1983), S. 595-597 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 54
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    Biotechnology and Bioengineering 25 (1983), S. 599-602 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
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  • 55
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: With carrot cells grown in semicontinuous culture with phosphate as limiting nutrient. Dougall and Weyrauch (1980) found that the steady-state culture density was different at different dilution rates. They suggested that the yield constant for biomass was different at different dilution rates. Here the yield constant for biomass for PO43-, NH4+, Mg2+, and glucose-limited semicontinuous cultures has been measured directly at two dilution rates. The yield constants for PO43-, NH4+, and Mg2+ but not for glucose are different at the two dilution rates. The effects of pH and temperature on the biomass yield constant was measured to extend the number of system parameters examined. Biomass yield constant was changed little with change from 25 to 28°C or from pH 4.2 to pH 5.5. The steady-state levels of anthocyanin were also measured. The responses of anthocyanin levels to the system parameters are different to the biomass responses. The data suggest that at different values of each of the system parameters, the composition and metabolic activities of the cells at steady state in semicontinuous cultures are different.
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  • 56
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    Biotechnology and Bioengineering 25 (1983), S. 745-759 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article is concerned with the development of a model to plan a strategy for an enzymatic batch process where enzyme is subjected to deactivation described by the inverted linear decay model. The particular system studied is the enzymatic hydrolysis of penicillin to 6-amino penicillanic acid (6 APA), but the model can be utilized with other batch systems as long as the decay of the immobilized enzyme (IME) preparation is described by the inverted linear decay model. The model developed is eminently practical and simple and several example of its application are shown. Experimental data obtained in a small pilot plant batch recirculated reactor on the average are well fitted by this model. For IME systems whose decay is best described by the first-order decay model, it is not possible to use the same approach.
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  • 57
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    Biotechnology and Bioengineering 25 (1983), S. 771-779 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A polymeric-resin-based microbiological assay is shown to yield results consistent with classical inhibition zone theory. This novel assay is applicable to cycloheximide, an antifungal antibiotic, at concentrations below 1.0 μg/mL and up to 800 μg/mL. Addition of ethanol to the cut-out wells of the assay plate helps to release the antibiotic and drastically increases the inhibition zone size. The antibiotic concentrations of both two component and multicomponent systems can be determined using this method. The use of polymeric-resin beads to monitor antibiotic concentrations is shown to be an effective technique for fermentation monitoring.
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  • 58
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    Biotechnology and Bioengineering 25 (1983), S. 761-770 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of chaotropic salts on the dissociation of ribonucleic acid from yeast nucleoprotein complex was studied. The effectiveness of various salts on the dissociation of ribonucleic acid followed the chaotropic series; i.e., Cl3CCOONa = NaClO4 〉 NaBr 〉 NaCl. Treatment of the nucleoprotein complex with 0.5M Cl3CCOONa or NaClO4 resulted in RNA removal of about 80%, whereas NaCl and NaBr removed only about 10 and 25%, respectively. Based on the results presented, a simple and novel method for industrial-scale preparation of single-cell proteins with low levels of nucleic acid is proposed.
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  • 59
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    Biotechnology and Bioengineering 25 (1983), S. 797-808 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Thirteen yeast species belonging to nine genera were screened for the production of single-cell protein (SCP) using cheese whey as the substrate. Cheese whey supplemented with minerals and yeast extract proved to the best medium for yield, lactose utilization, biomass production, and conversion efficiency. Production of β-galactosidase was studied in Brettanomyces anomalus, Kluyveromyces fragilis, Trichosporon cutaneum, and Wingea robertsii; the last proved to be the best strain combining high yield with shorter incubation period.
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  • 60
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    Biotechnology and Bioengineering 25 (1983), S. 809-844 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The use of computers in a fermentation pilot plant is described from a practical point of view. The aim is not the application of a computer to a single special process but a general application of computers to prepare and present data for the following analysis of fermentation processes. The hardware is normally bought from computer manufacturers, but some additional installations are useful. Application software has to be developed by the biotechnologist, therefore the software structure is the most important part of the computer application. Data storage is divided into three parts: short-time memory, long-time storage, and a medium memory mainly to be used in process analyses and process control. Four types of programs are used: main schedule tasks, low-priority on-line tasks, sense-switch routine, and different off-line programs. A table of all programs is presented, the main schedule task is described in detail to demonstrate the software structure.
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  • 61
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    Biotechnology and Bioengineering 25 (1983), S. 845-855 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A numerical treatment of the signal produced by an electrode onto which an artificial enzyme membrane is mounted can give the concentration of the substrate (glucose, saccharose, lactose, amino acids, etc.) in solution. In the example of a glucose analyzer, in which glucose oxidase catalyzes the oxidation of glucose, the computer receives pO2 level data from the electrode and calculates the glucose concentration. The transient electrode signal, measured as the enzyme membrane is exposed to a solution of glucose, is least-square approximated by a third-degree polynomial whose slope at inflection point is characteristic of the external glucose concentration. A calibration procedure provides a cubic spline approximation of glucose concentration as a function of slope, thus enabling automatic measurement of samples. The computer performs the calculations, and actuates valves for air rinsing, introduction of the sample, and water rinsing.
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  • 62
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    Biotechnology and Bioengineering 25 (1983), S. 929-938 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An experimental device was constructed to allow nearly simultaneous measurements to be made on temperature and gas composition at different depths in a solid-substrate fermentation bed. The time-dependent values of temperature, mol % O2 and mol % CO2 were measured at five positions in beds 6.35 cm (2.5 in.) deep. With a tempeh fermentation (Rhiopus oligosporus growing on soybeans) the temperature gradient could be as steep as 3°C/cm during active mold growth and concentration of CO2 could reach 21 vol. % in the bottom layer.
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  • 63
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    Biotechnology and Bioengineering 25 (1983), S. 1973-1980 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simple method of preparing a chitin-immobilized α-amylase and glucoamylase from the protease- and glycosidase-less Mutant HF-15 of Aspergillus awamori var. kawachi was developed and used for the production of high-glucose syrup. The glucoamylase was tightly bound onto chitin without the aid of a crosslinking agent because the enzyme contained a specific binding site for chitin. Continuous production of high glucose concentrate from a highly concentrated α-amylasetreated gelatinized starch substrate (about 45% total solids) was undertaken successfully with the use of a column-packed chitin-immobilized amylase. The activity of the column was stable for more than 20 days of continuous operation and the product was found to be only glucose with an average dextrose equivalent value of more than 97%. The final product showed no isomaltose or panose contamination, indicating that the immobilized amylase had no transglucosidation activity. The immobilized amylase was most active in the conversion of gelatinized starch to glucose at 55°C and pH 2.5 to 5.0. Drying the chitin-immobilized amylase resulted in the decrease of activity and shortening of storage life, whereas a storage life of up to 80 days was attained without affecting its original activity when kept under moist condition at 4°C.
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  • 64
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    Biotechnology and Bioengineering 25 (1983), S. 999-1011 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Whole cells of Escherichia coli B 10 having high tryptophan synthetase activity were used directly as an enzyme source to produce L-tryptophan from indole and L- or D,L-serine. This strain is tryptophan auxotrophic, which is tryptophanase negative and, in addition, L- and D-serine deaminase negative under production conditions. To avoid inhibition of tryptophan synthetase by a high concentration of indole, nonaqueous organic solvents, Amberlite XAD-2 adsorbent, and nonionic detergents were used as reservoirs of indole in the reaction mixture for the production of L-tryptophan. As a result, different effects were observed on the production of L-tryptophan. Particularly, among the nonionic detergents, Triton X-100 was very efficient. Using Triton X-100 for production of L-tryptophan from indole and L- or D,L-serine by whole cells of Escherichia coli B 10, 14.14 g/100 mL and 14.2 g/100 mL of L-tryptophan were produced at 37°C for 60 h.
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  • 65
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    Biotechnology and Bioengineering 25 (1983), S. 1013-1025 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Escherichia coli B 10, which has high activity of tryptophan synthetase, was grown in a 50-L batch culture in order to determine in which growth phase the cells have the highest specific tryptophan productivity. Accordingly, whole cells of the stationary phase were used for immobilization in polyacrylamide beads. After immobilization, these immobilized cells had 56% activity of tryptophan synthetase compared with that of free cells. First, the properties of immobilized cells were investigated. Next, discontinuous productions of L-tryptophan were carried out by using immobilized cells. In discontinuous production of L-tryptophan by the batch, the activity remaining of immobilized cells was 76-79% after 30 times batchwise use. In continuous production of L-tryptophan with a continuous stirred tank reactor (CSTR), the activity remaining of the immobilized cells was 80% after continuous use for 50 days. The maximum productivity of L-tryptophan in this CSTR system was 0.12 g tryptophan L-1 h-1.
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  • 66
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    Biotechnology and Bioengineering 25 (1983), S. 1027-1047 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Specific activities and the amounts of active immobilized enzyme were determined for several different preparations of α-chymotrypsin immobilized on CNBr-activated Sepharose 4B. Electron paramagnetic resonance (EPR) spectroscopy of free and immobilized enzyme with a spin label coupled to the active site was used to probe the effects of different immobilization conditions on the immobilized enzyme active site configuration. Specific activity of active enzyme decreased and rotational correlation time of the spin label increased with increasing immobilized enzyme loading. Enzyme immobilized using an intermediate six-carbon spacer arm exhibited greater specific activity and spin label mobility than directly coupled enzyme. The observed activity changes due to immobilization were completely consistent with corresponding active site structure alterations revealed by EPR spectroscopy.
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  • 67
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    Biotechnology and Bioengineering 25 (1983), S. 1049-1055 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The construction and performance of an enzyme electrode is described which specifically detects lower primary aliphatic alcohols in aqueous solutions. The electrode consists of a commercial Clark-type oxygen electrode on which alcohol oxidase (E.C. 1.1.3.13) and catalase were immobilized. The decrease in electrode current is linearly proportional to ethanol concentrations between 1 and 25 ppm. The response of the electrode remains constant during 400 assays over a period of two weeks. The response time is between 1 and 25 min. Assembly of the electrode takes less than 1 h.
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  • 68
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    Biotechnology and Bioengineering 25 (1983), S. 1057-1070 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The single-celled alga, Porphyridium cruentum, was assessed by means of chromatographic separation and mass spectral analysis of its fatty acids to be a potentially competetive source of arachidonic (5,8,11,14-eicosatetraenoic) acid. Models for both cell growth and production of the prostaglandin precursor at various temperatures and light intensities are presented. Increasing the light intensity within the range 1700-8000 lux increases the cell growth rate without affecting the arachidonic acid yield per cell; increasing the cultivation temperature from 18°C to ca. 32°C lowers the yield of arachidonic acid per cell but increases the rate of its production per unit volume and time. The increase of the weight ratio of arachidonic:palmitic acids at low temperatures is interpreted as a means of controlling the microviscosities of cellular membranes. In addition, the arachidonic acid content of cells decreases with the culture's age, despite increases in unit cell dry weight. The maximum rate of 0.46 mg arachidonic acid L-1 h-1 was calculated by means of the model to occur at ca. 32°C and 8000 lux in liquid cultures of 12 × 109 cells/L. Estimates of the cost of producing arachidonic acid by means of this alga range from $0.15/g to $1.00/g of arachidonic acid. Cells grown at 18°C in the presence of 0.3% linoleic acid swelled and produced gorlic (13-cyclopent-2-enyltridec-6-enoic) acid and another compound not normally observed. An estimated threefold increase of arachidonic acid content also occurred, but no significant lipogenesis was induced at 23°C in the presence of 1% kerosene or 0.3% palmitic, stearic, oleic, or linoleic acids.
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  • 69
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    Biotechnology and Bioengineering 25 (1983), S. 1095-1107 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Exomaltohexaohydrolase (E.C.3.2.1.98) was immobilized by radiocopolymerization of some synthetic monomers which were mixed in various combinations. Irradiation was carried out while the mixture of monomers and enzymes was frozen in petroleum ether-dry-ice bath. Recovery of the immobilized enzyme was 44-75%.The optimum pH of the enzyme slightly shifted to the acidic side. The pH stability was improved remarkably by immobilization. The enzyme was stable retaining more than 90% of its original activity in the range pH 4-11. The optimum reaction temperature of the enzyme increased about 2°C. Heat stability was also improved by immobilization, and that the enzyme retained about 40% of its original activity after treatment at 75°C for 15 min. The immobilized enzyme was stable to the repeated use of 20 cycles. The Km value of the enzyme for short-chain amylose was almost the same as that of native enzyme. When soluble starch was used as the substrate, the Km, value of the enzyme was three times as large as that of native enzyme. Effects of various metal ions and inhibitors on the immobilized enzyme were also studied compared to the native enzyme.
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  • 70
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    Biotechnology and Bioengineering 25 (1983), S. 2099-2101 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 71
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    Biotechnology and Bioengineering 25 (1983) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 72
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    Biotechnology and Bioengineering 25 (1983), S. 2103-2125 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In a nonmixed environment, bacterial population growth can be influenced significantly by cell motility properties as well as by growth kinetic properties. Therefore, in a situation of competition between two bacterial populations for a single chemical nutrient in a nonmixed environment, the outcome may depend upon the respective cell motility properties. In this article, the authors have presented a simple mathematical model for competitive growth of two randomly motile (i.e., possessing no chemotactic behavior) populations in a finite nonmixed region. An understanding of the behavior of this model should provide insight into the behavior of a number of common microbial competition problems. Analysis of this model yields the following results: (1) There may be as many as three possible non-trivial steady-state (or long-time) configurations: when species 1 survives, species 2 dies out; when species 2 survives, species 1 dies out; and species 1 and species 2 coexist. (2) The coexistence state can exist even though one species possesses a smaller intrinsic growth rate constant at all nutrient concentrations, if that same species is sufficiently less motile than the other species. (3) In fact, the species with the smaller maximum specific growth rate may grow to a larger population than the other. (4) The possibility of coexistence can be decided essentially from the results for single population growth.
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  • 73
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    Biotechnology and Bioengineering 25 (1983), S. 2149-2163 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The need for the determination of the free energy of formation of biomass in bioreactor second law balances is well established. A statistical mechanical method for the calculation of the free energy of formation of E. coli biomass is introduced. In this method, biomass is modelled to consist of a system of biopolymer networks. The partition function of this system is proposed to consist of acoustic and optical modes of vibration. Acoustic modes are described by Tarasov's model, the parameters of which are evaluated with the aid of low-temperature calorimetric data for the crystalline protein bovine chymotrypsinogen A. The optical modes are described by considering the low-temperature thermodynamic properties of biological monomer crystals such as amino acid crystals. Upper and lower bounds are placed on the entropy to establish the maximum error associated with the statistical method. The upper bound is determined by endowing the monomers in biomass with ideal gas properties. The lower bound is obtained by limiting the monomers to complete immobility. On this basis, the free energy of formation is fixed to within 10%. Proposals are made with regard to experimental verification of the calculated value and extension of the calculation to other types of biomass.
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  • 74
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    Biotechnology and Bioengineering 25 (1983), S. 2165-2176 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Activated sludge treatment of a pentachlorophenol (PCP)-containing synthetic waste was examined. With a waste containing some sugars, and 40-120 mg/L PCP, laboratory activated sludge required about seven days for acclimation. However, the prior addition of a quasipure culture of PCP-metabolizing Arthrobacter resulted in immediate acclimation. Even with acclimated sludge, however, the system was upset for two days by a simple step change from 40 to 120 mg/L of PCP. The stability of the system to such a shock load was considerably improved when a chemostat culture of the PCP-metabolizing Arthrobacter was fed slowly into the mixed liquor. Kinetic models were developed to describe the dynamic response of the system in terms of growth parameters, hydraulic detention time, sludge age, and bleed-in rate from the chemostat.
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    Biotechnology and Bioengineering 25 (1983), S. 1163-1168 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
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    Biotechnology and Bioengineering 25 (1983), S. 1169-1173 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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    Biotechnology and Bioengineering 25 (1983), S. 1175-1179 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
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    Biotechnology and Bioengineering 25 (1983), S. 1195-1200 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
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    Biotechnology and Bioengineering 25 (1983) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Biotechnology and Bioengineering 25 (1983), S. 1203-1203 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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    Biotechnology and Bioengineering 25 (1983), S. 2221-2230 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The contribution of the reversible thermal unfolding of an enzyme toward the overall irreversible thermoinactivation process has been examined both theoretically and experimentally. Using bovine pancreatic ribonuclease as a model, we have studied the effect of such variables as pH and salts both on the equilibrium constant of reversible denaturation and on the rate constant of the overall irreversible process. It has been demonstrated that at temperatures where a significant fraction of the enzyme molecules are in the native conformation, there is a correlation between the enzyme thermostabilities with respect to the reversible and irreversible inactivations: greater stability against the former is accompanied by greater stability against the latter. On the other hand, at very high temperatures (where essentially all of the enzyme molecules are unfolded), such a correlation does not exist. These findings are considered in terms of a kinetic model for irreversible enzyme thermoinactivation, and the implications of the derived relationship are discussed.
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    Biotechnology and Bioengineering 25 (1983), S. 1237-1250 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In 1979, a minicomputer system was developed for Hoffmann-La Roche by ABEC, Inc. for the purpose of achieving on-line analysis and reporting of data from 16 70-L pilot-plant fermentors (New Brunswick Scientific Co.). The system consists of a PDP 11/60 computer with 96K core capacity, two RL01 disk drives, two RX01 floppy-disk drives, LA-36 DECwriter terminal, Tektronix CRT, and Versatec printer plotter. DEC, PDP, RSX, RL01, RX01, LA-36, and DECwriter are trademarks of Digital Equipment Corporation. The computer software comprises three distinct groups of programs. RSX-11M is a disk-based operating system that allows quick response to realtime events, such as process monitoring and data acquisition, while carrying out less time-dependent activities, such as program development and graphical output. The AIM (Biles, Inc.) system is used to acquire and convert the voltage signals produced by pilot-plant instrumentation into engineering units. Analysis and graphical output are executed by ABEC and Versatec supplied programs. The most beneficial task performed by the computer is the production of graphical output of a variety of measured and analyzed data. This has led to an increase in personnel productivity and design of more meaningful experiments. An ancillary function of the system is to pick up data logged by a PDP 11/03 computer from a remote fermentation production plant by means of a MODEM interfaced communication link. Production data are analyzed and presented in a form identical with pilot-plant data. The experience with the system is discussed in this article.
    Additional Material: 11 Ill.
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  • 83
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1267-1293 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Interrelations between the rates of the product synthesis, cell biomass growth, respiration, and organic substrate consumption have been studied by the mass-energy balance method. This method is based on the utilization of a special unit of substance reducity, namely redoxon. Biochemical parameters have been found which are involved in these interrelations and which describe the processes of high-energy bond gain and energy expenditure during metabolism. In order to find these, the separation of the whole metabolism into several partial metabolisms has been applied. Equations have been obtained describing the dependences of the product yield and process specific productivity on the biochemical parameters and two macroscopic rates (e.g., rates of dilution and substrate consumption). Both aerobic and anaerobic product syntheses have been considered. The estimate of the upper limit of process productivity has been obtained. Mechanisms of the influence of the producer's intracellular characteristics on the rates of physiological processes and the culture productivity are discussed.
    Additional Material: 5 Ill.
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  • 84
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1419-1421 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Tab.
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  • 85
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1423-1434 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 7 Ill.
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  • 86
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1401-1418 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A general model of the transient behaviour of an oxygen probe is derived on more general assumptions than those previously considered. The present state of the art is shorly discussed in its relation to the newly derived equations: (1) the reducibility of the three-layer diffusional model to two-layer ones is discussed, and the two-layer model considering the membrane and the liquid film is verified experimentally, (2) experimental and theoretical treatments of transient probe characteristics determination are examined, and (3) the influence of chemical reactions of the first order as well as of zero order (microorgaganism respiration) in measured media on transientd probe characteristics is quantified.
    Additional Material: 8 Ill.
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  • 87
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1435-1439 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental runs on the inversion of sucrose by means of immobilized β-fructooxidase are reported. External mass-transfer and axial dispersion phenomena have been analyzed. It has been observed that external mass-transfer plays a significative role in the overall kinetics, while axial dispersion phenomena are negligible.
    Additional Material: 1 Ill.
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  • 88
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    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 25 (1983), S. 1441-1452 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microbiological transformation of benzaldehyde accomplished by the fungus Rhodotorula mucilaginosa immobilized in the ultrafiltration cell was studied. A polysulfone membrane formed on a sintered PVC support was used for the separation of the transformation product from the cellular material. Kinetic investigations have led to results which are typical of continuously fed stirred tank reactors (CFSTR) - the value of the maximum reaction rate (Vmax) and apparent Michaelis constant (K′m) are practically independent of the substrate retention time (calculated in terms of the flow intensity value). A strong relationship was found to occur between Vmax and biomass concentration in the reactor. Study of the apparent enzyme stability shows that the decrease in the biocatalyst activity is chiefly caused by penetration of the cells through the membrane. The experimental results were approximated in terms of the adopted mathematical model. Based on this model, the half-lives (t1/2) of enzyme activities were determined. The t1/2 value varies from 35 to 82 days and depends both on the permeate flux through the membrane and on the separation properties of the membrane.
    Additional Material: 6 Ill.
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  • 89
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    Weinheim : Wiley-Blackwell
    Electrophoresis 4 (1983) 
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 90
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    Weinheim : Wiley-Blackwell
    Electrophoresis 4 (1983), S. 1-19 
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Additional Material: 16 Ill.
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  • 91
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Sequential moving boundary electrophoresis with protons and hydroxyl ions as the sole counterions, consisting solely of six acids (system A) and of six bases (system B), gives rise to natural steady-state pH gradients similar to those predicted by theory (pH 2.4-5.5 for system A, pH 10.3-12.2 for system B). Mixtures of the constituents in system A and system B gave rise to a natural pH gradient spanning the pH range between the terminal electrolytes (pH 2.4 and 12.2) predicted for systems A and B. The predicted boundary displacement is negligibly small. Experimentally the boundary displacement could not be determined in view of the difficulty of separating it from the initial transient state in which the pH gradient is formed, and a final state in which the pH gradient decays.
    Additional Material: 6 Ill.
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  • 92
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The identification of turkey meat in food products has been accomplished using specific antisera against turkey troponin T. This protein (Mr 37 000) was extracted from fresh muscle tissue and isolated by a procedure that included free-flow electrophoresis as final fractionation step. Preparations of troponin T with purities of more than 95 % were applied as antigen in the immunization of rabbits. Several standard immunological techniques were used to determine additions of turkey meat in food products heated to different temperatures (including roasting temperature). That way, it was possible to also detect additions of chicken meat on the basis of a partial identity between troponins T from turkey and chicken muscle.
    Additional Material: 6 Ill.
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  • 93
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    Weinheim : Wiley-Blackwell
    Electrophoresis 4 (1983), S. 20-26 
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The moving boundary theory has been applied to the special case in which the proton and hydroxyl ion are the sole counterions. Moving boundaries between two monovalent weak acids, two biprotic acidic ampholytes, two weak bases and two biprotic basic ampholytes were considered. This application of the theory leads to constituent concentration relationships, values for pH and conductance of each phase and step pH gradients when sequential moving boundaries are considered. In addition, rigorous conditions for achieving the steady-state in such systems are also presented. Application of the theory allows for the prediction of the formation and displacement of pH gradients. In contrast to the classical theory of pH gradients formed by ampholytes, the establishment of inverse pH gradients and the electrophoretic displacement of natural pH gradients is clearly accounted for.
    Additional Material: 2 Ill.
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  • 94
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    Weinheim : Wiley-Blackwell
    Electrophoresis 4 (1983), S. 36-41 
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The progressive increase in circuit resistance observed at times in polyacrylamide gel electrophoresis is attributable in part to the formation of zones of altered salt concentration at the interfaces between gel and solution. Similar changes have been reported for electrophoresis through sucrose gradients. Such zones must develop wherever migrant ions suffer a change in transport number. The paper develops a basic theory for such concentration changes. It is shown that a moving boundary will tend to arise at any interface between two media, leaving behind it a zone of altered concentration. The effect will in general be most noticeable at low ionic strengths and with electrolytes whose ions differ considerably in size, a condition applying to many common buffers. Where both ions are relatively small, diffusion is likely to obscure the boundary movement, but this will not affect the integrated change in concentration. The effect could have various deleterious consequences in gel electrophoresis, particularly in preparative apparatus. There are also implications for techniques such as isoelectric focusing and for the analysis of membrane phenomena.
    Additional Material: 3 Ill.
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  • 95
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Macromolecules isolated from human erythrocyte membranes which expressed I/i and ABH blood group activities were analyzed by quantitative immunoelectrophoretic techniques in order to determine the distribution of and the relationship between these two blood group systems. To help in these studies a rocket immunoelectrophoretic assay, with a maximum sensitivity of 10 ng, was developed which could detect and quantitate erythrocyte macromolecules which expressed I/i and A and B blood group determinants. In addition, a modification of the tandem crossed immunoelectrophoresis technique was also used to elucidate the structural relationship between determinants of these systems on one of the isolated macromolecular species. Serological and other immunological data are presented which throughly support the immunoelectrophoretic results. From these studies we have concluded that I and most likely i antigenic determinants are primarily expressed on poly(glycosyl)ceramides (i. e. macroglycolipids) and possibly to a lesser extent on Band 3. I active poly(glycosyl)ceramide could be isolated in equal quantity from any adult ABH type erythrocyte; i activity was found in similar quantity in the same fraction isolated from one i adult erythrocyte population. Besides expressing I/i activity the various poly(glycosyl)ceramide fractions also exhibited A, B or H activity as well, dependent upon the ABH cell type from which they were isolated. Unlike the equal distribution of I, however, ABH activity was type-specific in that the poly(glycosyl)ceramide isolated from type A (either A or Ai), B or 0 cells could react only with anti-A, anti-B, or Ulex anti-H lectin, respectively. Using the modified tandem crossed immunoelectrophoresis (CIE) technique, it was established that the same glycolipid molecules which carry I blood group activity express the A and B determinants as well. Band 3 material isolated from 0 erythrocytes exhibited I, i and H activities. From CIE analysis the I activity of Band 3 appeared to reside in a subpopulation of this material.
    Additional Material: 5 Ill.
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  • 96
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Search strategies for finding spot differences among multiple two-dimensional (2-D) polyacrylamide electrophoresis gels are discussed in the context of the GELLAB spot data base management system. A 2-D gel experiment should have a well-defined biological experimental and preparation protocol reflecting the hypotheses of the problem. So too should the analysis of its corresponding 2-D gel computer spot data base have a protocol. This protocol is heavily influenced by the nature of the biological experiment as well as 2-D gel preparation considerations including the realities of artifactual and systematic noise. It is further influenced by constraints due to computational considerations. The search strategy is that part of the analysis protocol in which an experimenter iteratively defines tests to find significant spot differences. One goal of designing a well thought out search protocol is to reduce the number of search iterations required. Aspects of some requirements and constraints for useful search strategies are discussed.
    Additional Material: 10 Ill.
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  • 97
    ISSN: 0173-0835
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: We describe a system for accurate photometry and analysis of two-dimensional (2-D) gels, and its application to both high and low resolution gels. Image acquisition is video-based and includes methods of data correction necessary for accurate photometry. The analysis is based upon a method described previously by Lutin et al. [8], which we have modified for improved stability and adapted to run on our PDP 11/60 computer. We illustrate analysis of a typical gel with a sequence of images showing the data while Gaussian components are estimated, removed, added and fitted as the iterative algorithm proceeds. We conclude by demonstrating the use of a mathematical curve-of-growth model for calibrating peak volumes vs. protein loading.
    Additional Material: 10 Ill.
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  • 98
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    New York, NY [u.a.] : Wiley-Blackwell
    Cell Biochemistry and Function 1 (1983), S. 168-172 
    ISSN: 0263-6484
    Keywords: Bone ; aerobic glycolysis ; fatty acid oxidation ; cartilage ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The apparent paradox of aerobic glycolysis has been investigated in bone and in cartilage. A new cytochemical procedure for hydroxyacyl dehydrogenase (HOAD) activity showed that the maximal activity of this enzyme in both tissues was equivalent to the maximal activity of glyceraldehyde 3-phosphate dehydrogenase (GAPD). The sum of these activities gave a measure of the maximum amount of acetyl-coenzyme A that could be produced. In these tissues, but not in liver which does not exhibit aerobic glycolysis, this summed value exceeded the maximal activity of succinate dehydrogenase (SDH). Consequently, it suggested that where fatty acid oxidation is sufficient to supply all the acetyl-coenzyme A required for the Krebs' cycle, that derived from fatty acid oxidation may inhibit pyruvate dehydrogenase causing accumulation of pyruvate which must be converted to lactate if pentose-shunt activity is to be maintained.
    Additional Material: 2 Ill.
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  • 99
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    New York, NY [u.a.] : Wiley-Blackwell
    Cell Biochemistry and Function 1 (1983), S. 2-2 
    ISSN: 0263-6484
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 100
    ISSN: 0263-6484
    Keywords: Endocrine system ; zona glomerulosa ; aldosterone ; 18-hydroxycorticosterone ; steroid-protein complexes ; cell suspensions ; collagenase ; trypsin ; corticotrophin ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: While in vitro incubation of dispersed cell preparations of adrenal cell types has been widely used as an experimental model, few studies have addressed the possibility that the enzymic and mechanical treatments involved may affect tissue functions. Using rat adrenal whole capsule tissue, consisting of glomerulosa cells still attached to the connective tissue capsule together with some fasciculata cells, and dispersed glomerulosa cell preparations formed by a variety of enzymic and incubation treatments, striking differences have been demonstrated between the functions of the various preparations in vitro. Under ACTH stimulation, whole capsules produced (ng per pair ± s.e.) 405 ± 35 ng aldosterone, 650 ± 60 ng 18-hydroxycorticosterone (18-OH-B) and 850 ± 90 ng corticosterone. In cells dispersed by collagenase incubation followed by repeated pipetting and filtration, aldosterone and 18-OH-B yields under ACTH stimulation fell to values less than 10% of those produced by whole tissue, whereas corticosterone values were unchanged. Omitting the filtration step gave a less well marked decline in aldosterone and 18-OH-B to 50% of intact tissue values. When the tissue was not dispersed after collagenase incubation, aldosterone and 18-OH-B outputs were similar in the two preparations. The decline in aldosterone and 18-OH-B is not attributable to loss in cell-cell contact alone, since short term culture of collagenase dispersed cells on contracting collagen discs did not restore the capacity to produce these steroids, and a decline in their output also occurred in similar culture of intact capsule tissue. In acute incubations, hyaluronidase had similar effects to collagenase, whereas trypsin, papain and a bacterial protease evoked aldosterone release during the preincubation period, but did not affect subsequent yields of aldosterone and 18-OH-B in incubations of dispersed (but not filtered tissue) in the presence of ACTH. Chymo-trypsin had no effect on preincubation but eliminated subsequent response to ACTH in all incubation conditions. Together with previously published data on the effects of trypsin, the results support the view that in intact rat adrenal glomerulosa tissue, aldosterone and 18-OH-B are sequestered into intracellular stores in the form of novel steroid-protein complexes. These are hydrolysed by trypsin and other preoteases with consequent release of steroid, but are virtually eliminated by conventional methods of cell suspension preparations, using collagenase preincubation with subsequent mechanical dispersal and filtration.
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