Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (323)
  • 1975-1979
  • 1890-1899
  • 1991  (323)
  • Genetics  (192)
  • Life Sciences  (131)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 81 (1991), S. 50-58 
    ISSN: 1432-2242
    Keywords: Vicia faba ; Legumin ; Vicilin ; Structure ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Legumin and vicilin were purified from seeds of Vicia faba L. var. Scuro, characterized in different electrophoretic systems, and used to produce polyclonal antibodies in rabbits. Two-dimensional electrophoretic studies showed a wide range of heterogeneity in the subunits of both legumin and vicilin. Legumin was found to be composed of 29 disulphide-linked subunit pairs with different molecular weight and/or isoelectric point. Western blot analysis of legumin of several mutants revealed molecular polymorphism based on a corresponding gene family. Three different α-major legumin patterns were found, and inheritance studies showed that the 34.3-kD legumin polypeptide is the product of one locus, Lg-1α, which is the first legumin genetic locus described in Vicia faba. Vicilin was found to be composed of as many as 59 subunits distributed in a molecular weight range of 65.7 to 42.8 kD (major polypeptides) and 37.2 to 15.2 kD (minor polypeptides), with different isoelectric points. A model is proposed that explains the possible formation of the minor subunits and the major subunits of 48.2 and 46 kD molecular weight (MW) from proteolytic cleavages and/or glycosilation of precursor polypeptides. Ten different vicilin electrophoretic patterns were observed among the analyzed accessions, which showed large molecular polymorphism that proved to be under genetic control.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 82 (1991), S. 761-764 
    ISSN: 1432-2242
    Keywords: Rye ; Male sterility ; Genetics ; Gene location ; Trisomies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genetics and relationships between the genes in rye located in the nucleus and cytoplasm of the male sterility of the G-type were investigated. A factor inducing male sterility was found in the cytoplasms or rye cv Schlägler alt and rye cv Norddeutscher Champagner. Monogenic inheritance was observed in linkage tests. Using primary trisomies of rye cv Esto, the nuclear gene ms1 was found to be located on chromosome 4R. Modifying genes, probably masked in normal cytoplasm but expressed in male-sterility-inducing cytoplasm together with gene ms1, were located on chromosomes 3R (ms2) and 6R (ms3). Mono-, di-, and trigenic inheritance types were found in backcross progenies of trisomies.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 86 (1991), S. 243-250 
    ISSN: 1432-1939
    Keywords: Daphnia ; Life-history ; Genetics ; Variation ; Maturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Life-history traits of 101 clones from two populations of Daphnia magna were measured under controlled environmental conditions in the laboratory. Some individuals had four juvenile instars, others had five. This depended on their length at birth and on the population they came from. Females in the group with five juvenile instars were smaller at birth but larger and older at maturity than those with four juvenile instars. Within groups of females with equal numbers of preadult instars (instar groups) age and size at maturity increased with size at birth. This relationship differed significantly among instar groups for both age and size at maturity. Significant differences in age and size at maturity between two populations became non-significant when size at birth was used as a covariable in AN-COVA. Within populations, size at birth depended on the clone and on the parity of the clutch. First-clutch offspring were considerably smaller than those from later clutches. The results suggest that variability in life-history traits is common within and between clones, but that most of this variation can be accounted for by size at birth and the number of pre-adult instars.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0428
    Keywords: Genetics ; diabetes mellitus ; restriction fragment length polymorphism ; glucose-transport ; familial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Patients with Type 2 (non-insulin-dependent) diabetes mellitus and a strong family history of the disease may represent a sub-group where genetic factors play a pree-minent role in transmission of the disease. A defect in the liver/islet cell glucose transporter (GluT 2) could explain many of the pathophysiological features of the disease. In order to test the hypothesis that genetic variation at the GluT 2 locus contributes genetic susceptibility to Type 2 diabetes, 60 unrelated Caucasian diabetic patients with at least one affected sibling were genotyped for a Taq 1 restriction fragment length polymorphism marker. Hybridisation with a cDNA GluT 2 probe identified two alleles of sizes 13 kilobase (T1) and 19 kilobase (T2). The allele frequencies in the diabetic group with a family history were significantly different from those in a racially-matched control population of 122 subjects with no personal or family history of the disease (diabetic patients T1=0.96, T2=0.04, control subjects T1=0.89, T2=0.11, p〈 0.03). However, when the study was repeated with 54 diabetic patients with indeterminate family history, statistical significance was not reached although the allele frequencies showed a similar trend. The findings of this study support the hypothesis that a genetic variant of the liver/islet cell glucose transporter may contribute to familial susceptibility in Type 2 diabetes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-072X
    Keywords: Carboxydotrophic bacteria ; Ribulosebis-phosphate carboxylase ; Phosphoribulokinase ; Hybridization ; Plasmids ; Genetics ; CO2 fixation ; Alcaligenes eutrophus ; Pseudomonas carboxydovorans ; Rhodospirillum rubrum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heterologous gene probes derived from cfxLp and cfxPp genes of Alcaligenes eutrophus H16 revealed the presence of structural genes encoding ribulosebisphosphate carboxylase (Rubisco) and phosphoribulokinase (PRK) on the genome of carboxydotrophic bacteria. The two genes were found to be rather conserved. In Pseudomonas carboxydovorans OM5 cfx genes reside on the plasmid pHCG3 and the chromosome as well, indicating that they are duplicated. Also in all plasmidharboring carboxydotrophic bacteria cfxL and cfxP structural genes were found to be plasmid-coded. Our results extend the list of carboxydotrophy structural genes residing on the plasmid pHCG3 and strongly support the idea that the components essential for the chemolithoautotrophic utilization of CO by Pseudomonas carboxydovorans OM5 are plasmid-coded. A cfxL gene probe from Rhodospirillum rubrum did not detectably hybridize with DNA from any of the carboxydotrophic bacteria examined.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Annals of hematology 62 (1991), S. 188-189 
    ISSN: 1432-0584
    Keywords: Hemochromatosis ; Pyruvate kinase deficiency ; Hereditary anemia ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hemochromatosis has been reported in several patients with chronic hemolytic anemia due to pyruvate kinase deficiency. We describe here a further patient with such an association and review the literature on the subject. We hypothesize that iron overload may occur in patients with pyruvate kinase deficiency who are also carriers of the hereditary hemochromatosis gene.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0428
    Keywords: Genetics ; Type 1 (insulin-dependent) diabetes mellitus ; Type 2 (non-insulin-dependent) diabetes mellitus ; HLA ; haptoglobin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Epidemiologic data suggest that having a parent with Type 2 (non-insulin-dependent) diabetes mellitus increases the risk for Type 1 (insulin-dependent) diabetes in siblings of a Type 1 diabetes proband. This increase in risk is consistent with a shared genetic susceptibility between Type 1 diabetes and Type 2 diabetes. We contrast genetic risk factors in three sets of families, consisting of (1) a single Type 1 diabetic child (proband) and non-diabetic parents, (2) multiple Type 1 diabetic siblings and non-diabetic parents, and (3) at least one Type 1 diabetic child and at least one Type 2 diabetic parent. Previous studies have demonstrated that HLA region genes, which elevate the risk in Type 1 diabetes, have no significant effect with respect to the risk for developing Type 2 diabetes. An earlier report cited a contribution by the haptoglobin locus to genetic susceptibility for Type 2 diabetes. We provide evidence that a high risk HLA antigen (HLA-DR3) is decreased to a greater extent in Type 1 patients with a Type 2 parent than in Type 1 patients in which the parents are not diabetic. The role of HLA-DR4 is maintained in these families, with an unexpectedly significant increased rate of transmission of the HLA-DR4 allele from Type 2 parent to Type 1 offspring. The role of haptoglobin in these families does not appear to be important, either with respect to association with diabetes or with respect to linkage with a secondary susceptibility locus. These results indicate that families with a Type 2 parent and Type 1 child, heavily determined by HLA-DR4 linked factors, may represent a homogeneous subset of diabetes susceptibility.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 83 (1991), S. 24-32 
    ISSN: 1432-2242
    Keywords: Genetics ; Growth curve ; Body weight ; Chickens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetic improvement in growth of poultry has traditionally proceeded via selection for body weight at a fixed age. Due to increased maintenance costs and reproductive problems of adult broiler breeders, the potential for genetic manipulation of the growth curve has been receiving increased interest. Research of both male and female progeny of a three-way diallel cross was used to investigate the inheritance of growth curve parameters. The Laird form of the Gompertz equation was used to determine growth curve parameters, and was suited to the juvenile growth data frequently collected from meat-type chickens. Growth rate exhibited significant heterosis due to both autosomes and the sex chromosomes. Age at inflection point also exhibited significant average heterosis, though only among females. Growth rate was also influenced by average line effects, as was age at inflection point. Maternal effects had no influence on growth curve parameters, while additive sex linkage was observed for growth rate. Phenotypic and genetic correlations were calculated among the growth curve parameters and suggest that specific breeding programs could alter the growth trajectory of the contemporary broiler chicken. Moderate heritabilities were observed for the growth curve parameters and support the hypothesis that the growth curve could be altered via genetic manipulation of early postnatal growth, especially during the first 14 days post-hatch.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 82 (1991), S. 771-776 
    ISSN: 1432-2242
    Keywords: Secale cereale ; RFLP ; α-Amylase ; Genetics ; Isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Rye α-Amy1, α-Amy2, and α-Amy3 genes were studied in the cross between inbred lines using wheat α-amylase cDNA probes. The α-Amy1 and α-Amy2 probes uncovered considerable restriction fragment length polymorphism, whereas the α-Amy3 region was much more conserved. The numbers of restriction fragments found and the F2 segregation data suggest that there are three α-Amy1 genes, two or three α-Amy2 genes, and three α-Amy3 genes in rye. These conclusions were supported by a simultaneous study of α-amylase isozyme polymorphism. The F2 data showed the three individual α-Amy1 genes to span a distance of 3cM at the locus on chromosome 6RL. The genes were mapped relative to other RFLP markers on 6RL. On chromosome 7RL two α-Amy2 genes were shown to be separated by 5 cM. Linkage data within α-Amy3 on 5RL were not obtained since RFLP could be detected at only one of the genes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 104 (1991), S. 17-21 
    ISSN: 1432-2072
    Keywords: MK-801 ; Phencyclidine ; Ketamine ; CGP 39551 ; CGS 19755 ; NPC 12626 ; Locomotor activity ; Genetics ; NMDA/glutamate receptor complex ; Mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of non-competitive (MK-801, phencyclidine, and ketamine) and competitive (CGP 39551, CGS 19755, and NPC 12626) N-methyl-d-aspartate (NMDA) receptor antagonists on locomotor activity in inbred CBA and C57, and in outbred NMRI mice were examined. Administration of the non-competitive NMDA antagonists produced a dose-dependent increase in well-coordinated locomotor activity at lower doses, followed by a bizarre behavioral syndrome (head weaving, body rolling, rotations, ataxia) after higher doses. The pharmacological profile of the competitive antagonists CGP 39551, CGS 19755, and NPC 12626 was more complex. CGP 39551 dose-dependently inhibited locomotor activity, whereas CGS 19755 and NPC 12626 displayed a biphasic action, that is low doses inhibited locomotor activity, whereas higher doses produced mild behavioral stimulation. The behavioral effects of NMDA antagonists appear to be genetically determined, since CBA animals were most sensitive to both noncompetitive and competitive antagonists, followed by NMRI and C57 animals. The differential effects of NMDA antagonists in various strains of mice suggest that the observed behavioral differences may be due to genetic differences in the NMDA/glutamate receptor channel complex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1432-2072
    Keywords: Habituation ; GABA ; Ethanol sensitivity ; Ethanol tolerance ; Genetics ; Mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Habituation to a test environment following daily exposure for 5 days was examined in three genetically different strains of mice. C57 animals showed significant habituation to the new environment already on the second day. The habituation of NMRI mice was significant on the third day, whereas CBA mice showed no habituation at all during the experimental period. There was no difference between the animal strains in learning capacity in a passive avoidance test, but CBA mice displayed a significant increase in latency in their performance. When tested for sensitivity to the convulsant actions of GABAergic antagonists, picrotoxin produced seizures at lower doses in CBA as compared to NMRI and C57 mice, whereas there was no difference between the strains in the seizure activity produced by the specific GABA receptor antagonist bicuculline. When the animals were tested for sensitivity to ethanol in a horizontal wire test, ethanol (2 g/kg, IP) produced muscle relaxation in CBA mice whereas the performance of NMRI and C57 was not affected. A large dose of ethanol (4 g/kg, IP) produced a significantly longer sleeping time in CBA mice as compared to NMRI and C57 animals. Ethanol-produced hypothermia was, however, similar in all animals. Environment-dependent development of tolerance to ethanol following daily injections of ethanol for 4 days was examined. C57 mice showed the most rapid development of tolerance towards ethanol's hypnotic actions, whereas CBA mice showed no tolerance to this effect of ethanol. No difference between the strains to the development of tolerance to ethanol's hypothermic effects was observed. The present findings indicate that sensitivity to ethanol and ethanol tolerance are complex phenomena which cannot be adequately characterized by measuring only one single functional response to ethanol. The possibility that a genetically determined perturbation in the functions of the GABA receptor-coupled chloride channel, noted as variable sensitivity to picrotoxin, may be of importance for the observed disturbance in habituation to a new environment, for the different sensitivity to ethanol, and for the different rate of development of ethanol tolerance is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 60 (1991), S. 173-182 
    ISSN: 1570-7458
    Keywords: Genetics ; evolution ; host adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When populations are exposed to different environments, evolutionary processes can lead either to genetically differentiated strains or to the appearance of increased generalism at the individual level. For evolution to occur, genetic variability in performance in different environments is required. Here, intraspecific genetic variation across environments was estimated in the flour beetle Tribolium castaneum (Herbst) by comparing the responses of two strains of T. castaneum to different flour types. Replicated groups from each strain were allowed to develop on either the standard whole wheat medium or on one of four novel flours (wheat, rice, corn and oat). In several of the novel flours, clear differences in mean development time or population size of one or both strains were seen relative to performance in the standard medium. Moreover, the strains differed significantly in their phenotypic responses to the flours. One strain did particularly poorly on oat flour. Reduced oviposition, reduced larval survivorship and increased larval cannibalism were examined as possible causes of the low productivity on oat flour. These three factors accounted for about 70% of the reduction in population size when this strain oviposited and developed in oat flour. The difference between these two outbred strains in response to these five flours suggests that genetic variation in resource use is present within T. castaneum and may also be present within strains and natural populations in grain storage facilities. Such variation would permit an evolutionary response to selection in multiple environments (flours). This process has agricultural implications when several types of grain are stored in a single location because it could eventually lead to the evolution of highly generalized populations of T. castaneum, an important pest of stored products.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1572-8773
    Keywords: Iron transport ; Siderophores ; Pseudomonas putida ; Genetics ; Receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Root-colonizingPseudomonas putida WCS358 enhances growth of potato in part by producing under iron-limiting conditions a yellow-green, fluorescent siderophore designated pseudobactin 358. This siderophore efficiently complexes iron(III) in the rhizosphere, making it less available to certain endemic microorganisms, including phytopathogens, thus inhibiting their growth. At least 15 genes distributed over five gene clusters are required for the biosynthesis of pseudobactin 358. High-affinity iron(III) transport in strain WCS358 is initiated by an 86-kDa outer membrane receptor protein (PupA) which appears to be specific for ferric pseudobactin 358. PupA shares strong similarity with TonB-dependent receptor proteins ofEscherichia coli, which suggests a TonB-like protein in strain WCS358 is required for iron(III) transport. Strain WCS358 possesses a second uptake system for ferric pseudobactin 358 and structurally diverse ferric siderophores produced by other microorganisms. A second receptor gene (pupB) responsible for iron transport from pseudobactin BN7 or pseudobactin BN8 has been identified. The production of this and certain other ferric siderophore receptor proteins requires that strain WCS358 be grown in the presence of these siderophores. An apparent regulatory gene required for the expression ofpupB is located adjacent topupB. Two positive regulatory genes have been identified which can independently activate, under low-iron(III) conditions, transcription of genes coding for the biosynthesis of pseudobactin 358.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1437-160X
    Keywords: Immunoglobulin allotypes ; Systemic lupus erythematosus ; Genetics ; Gm ; Km ; HLA-antigens ; Autoantibodies ; Clinical symptoms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunoglobulin heavy chain (G1m, G2m, G3m, A2m) and kappa light chain (Km) allotype and phenotype frequencies of 323 central European Caucasian patients with systemic lupus erythematosus (SLE) were examined and correlated with various genetic, serologic and clinical markers of SLE. No significant associations were found between immunoglobulin allotypes or phenotypes and all 20 parameters tested (nephritis, vasculitis, arthralgias, photosensitivity, discoid lesions, central nervous system disease, Raynaud's phenomenon, sex, anti-Ro, anti-La, anti-nRNP, HLA-DR1-DR7, HLA phenotypes B8-DR3, B7-DR2). It could therefore be assumed that Gm, A2m and Km allotypes were not associated with HLA-antigens and had no influence on the serologic and clinical expression of SLE.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    European journal of epidemiology 7 (1991), S. 490-493 
    ISSN: 1573-7284
    Keywords: Creutzfeldt-Jakob diseases ; Prion disease ; Jews ; Libya ; Genetics ; Pathophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The focus of CJD among Jews of Libyan origin has been recognized for two decades, but the reasons underlying it were unknown. Prevailing views suggested transmission from sheep infected with scrapie. However, recent data show that in fact CJD in this ethnic group is a genetically determined disease due to a point mutation on the codon 200 of the prion protein gene. The clinical characteristics of CJD in this group, and particularly the less common periodic activity in the EEG, are reviewed. New findings include peripheral neuropathy of the demyelinating type in two cases, presumably due to involvement of Schwann cells. The pathophysiology of the disease includes, presumably, a focal post-translational modification of the prion protein, (predisposed by the mutation). Later, the disease progresses through cell-to-cell transmission.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1573-6903
    Keywords: Genetics ; catecholamine ; brain ; imprinting ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study was designed to compare catecholamine concentrations among three brain areas of four pureline populations of visually isolated chicks. The purelines used were a commercial male line, a fertility selected line, an unselected fertility control line, and unselected White Jersey Giants. In general, male chicks had significantly larger brain weights than females. Six catecholamine-related compounds (norepinephrine, epinephrine,l-DOPA, dopamine, DOPAC, and MHPG) were measured via HPLC-ECD. No significant differences in neurochemical concentration were observed for any line or brain area due to sex of the chick. The hypothalamus (HT) contained the greatest concentration of catecholamines in all lines, followed by the intramedial hyperstriatum ventrale (IMHV) and optic tectum (OT). The HT exhibited consistent lateralization in all lines with the right HT containing ca. 30% more catecholamines than the left HT. While no consistent lateralization was observed among the other brain areas, the IMHV exhibited significantly different degrees of lateralization among the populations. Neuronal activity, as measured by MHPG:NE and DOPAC:DA ratio varied by line within each brain area. There were line differences for MHPG:NE in the HT, IMHV, and OT, while line differences for DOPAC:DA were observed in the HT. Since differences among purelines have been demonstrated in this study, care must be given to precisely define the genotype of chicks used in behavioral and neurochemical research.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1573-5060
    Keywords: Brassica oleracea ; Cauliflower ; Stalk rot ; Screening ; Genetics ; Resistance ; Sclerotinia sclerotiorum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The inheritance of resistance in cauliflower to stalk rot (Sclerotinia sclerotiorum (Lib.) de Bary) was investigated in population from six generations of six crosses. Disease incidence was recorded on 4 parents, 6 Fs 1, 6 Fs 2 and 12 back-crosses in a screenhouse under artificially created epiphytotic conditions. Resistance to stalk rot in this set of parents was found to be polygenic and under the control of recessive genes and due primarily to additive gene action. A breeding strategy emphasizing recurrent selection should lead to improvement in resistance.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 240 (1991), S. 188-190 
    ISSN: 1433-8491
    Keywords: Families ; Genetics ; Polydiagnostic approach ; Schizophrenia ; Swedish family complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A polydiagnostic computerized diagnostic system for psychosis was used in a Swedish family complex, and 51 patients with psychiatric symptomatology were examined with eight main diagnostic systems for schizophrenia and three systems for schizophrenic subgroups. All patients fulfilled the criteria for schizophrenia according to Taylor et al., 50 according to Carpenter, 41 according to RDC, and 31 of the 51 according to DSM-III and DSM-III-R. The hypothesis that the patients in the Swedish family complex differ from other phenotypes of schizophrenia must be refuted based on the data of the present study.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 228 (1991), S. 361-371 
    ISSN: 1617-4623
    Keywords: Plant ; Hormone ; Genetics ; Hypocotyl ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated nine independent auxin-resistant mutants of Nicotiana plumbaginifolia by culturing M2 seedlings in the presence of indole-3-acetic acid ethyl ester or 1-naphthaleneacetic acid at concentrations which significantly inhibit hypocotyl elongation of the wild type. The mutations were induced by treating seed with ethyl methanesulphonate and were found in the course of screening 10 000 individual M2 families. Auxin resistance was in all cases the result of a mutation at a single, nuclear locus. The dominance relationships of two of the mutants could be defined as recessive or dominant; all other mutants showed partial dominance. In contrast to previously described mutants of Arabidopsis and N. plumbaginifolia, all of the present mutants were specifically resistant to auxin; the mutants were cross-resistant to several auxins, but showed no increased resistance to cytokinin, abscisic acid, ethylene or 1-amino-cyclopropane-1-carboxylic acid. The importance of the choice of the selection criterion for the isolation of specific resistance traits is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 9-14 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: It was applied a macroscopic energy balance to a solid state fermentation process and an electron balance in order to estimate the temperature and the heat evolved in the process. There were employed several equations that describe the development of the system and offer the possibility to design or control such fermentations.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 14-14 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 23-29 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The use of the expensive IPTG for induction of the tac-promoter is not practicable at the industrial scale because of the large amounts necessary for induction. We developed a system in which IPTG as inducer was replaced by lactose which induces the tac-promoter with the same efficiency. In E. coli CW3011 (pOF1.0) lactose is utilized as inducer and carbon source even in the presence of glucose, presumably as a consequence of the overproduction of lac-permease.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 31-37 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Three yeast strains were isolated from a spontaneously fermented native millet (Pennisetum typhoideum) malt beer (Oyokpo). One of the yeast isolates found to have the most highly fermenting capacity was characterised and identified as a strain of Saccharomyces cerevisiae. The yeast was then utilised as the pitching yeast in a subsequent controlled fermentation of millet wort at 20°C for 120 hours. Bitter leaf (Vernonia amagdalina) extract was used as the bittering and flavouring agent. The Oyokpo beer sample produced under these conditions was found to possess both chemical and organoleptic qualities comparable to some extent, to the conventional barley malt beer. At the end of fermentation, the pH, specific gravity, alcohol content, reducing sugar content and protein content of the beer were 4.11, 1.0308, 2.81% (v/v), 4.00 (mg/ml) and 0.84 (mg/ml) respectively.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 37-37 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 38-38 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 38-38 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 39-48 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two isoenzymes of chorismate mutase (EC 5.4.99.5), designated as CM-1 and CM-2, were isolated and partially purified from suspension-cultured cells of Ruta gravelens by DEAE-sephacel chromatography and gel filtration. 60-72% of the total activity measured after DEAE-sephacel chromatography were obtained as CM-1 and 28-40% were CM-2 activity. CM-1 was inhibited by phenylalanine (K1 = 4 · 10-6 M) and tyrosine (K1 = 8. 10-6M) and activated by tryptophan. In contrast, CM-2 was not influenced by these three amino acids. The molecular weights estimated by gel filtration on SEPHADEX G-150 were 56000 for CM-1 and 45000 for CM-2, respectively. Both isoenzymes were stable at -20°C, but exhibited different behaviour during thermal inactivation and different optima of reaction temperature. CM-1 catalysed the reaction at a pH optimum of pH 7.8 and CM-2 showed a broad optimum between 6-10. The Km-values for chorismic acid were determined to be 1.1 mM for CM-1 and 0.5 mM for CM-2. The isoenzymes showed different behaviour to inhibitors of sulfhydryl groups. There were no differences in all parameters of chorismate mutase examined for two various cell lines of Ruta graveolens.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 73-76 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new metabolite, identical with dehydroaltenusin was isolated from a strain Talaromyces flavus B 5 which was selected from parental strain 51 C/I. Metabolite inhibited the growth of wooddamaging fungi, especially Ciadosporium sphaerospermum and P388 leukemid cells.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bradyrhizobium sp. isolated from the root nodules of a leguminous shrub, Crotalaria retusa L., produced a high amount of indole acetic acid (IAA) from tryptophan in the culture. The bacteria preferred D-isomer to the DL- or L-isomer of tryptophan for the IAA production. The IAA production could be increased up to 153.6% over control by supplementing the medium with arabinose (0.5%), ZnSO4(0.01 μg/ml), KNO3 (0.1%), thiamine-HCl (0.01 μg/ml) and EDTA (5 μg/ml).The possible role of the rhizobial production of IAA with the rhizobia-legume symbiosis is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 449-456 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The production of genetically engineered antibodies in Escherichia coli is now possible. The resulting fragments are completely functional and have antigen binding constants industinguishable from the natural antibody. This article summarizes the biochemical basis of this newly developed technology and the properties of the resulting fragments. It is likely that this technology will have an important role in antibody production for technical, medical and research uses. Screening of E. coli libraries may mount a challenge to traditional antibody production methods.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 457-466 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The determination of an optimum feeding profile of a fed-batch fermentation requires the solution of a singular optimum control problem, which is often complicated by changes in the process kinetics during the fermentation. The procedure of optimization may be sufficiently simple, if the feeding part of fermentation is carried out in the quasi-steady state. In this work an algorithm for operating a fed-batch fermentation using mentioned regime is offered. The algorithm supposes a periodical correction of the feeding strategy. Applying to fed-batch lysine fermentation demonstrate efficacy of this algorithm over frequently used strategies.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 467-477 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics based on the MONOD conception of anaerobic, discontinuous, isothermal, isobaric fermentation producing a special protein in secondary metabolism is studied.The kinetic analysis results in a growth limitation by the primary product which shows a sigmoidal behaviour, a lineary correlation between the specific substrate degradation and the specific rate of formation lactic acid and a lineary correlation in a good approximation between the formation of proteins and substrate degradation.In this study a process model with coupled differential equations is provided. Kinetic and stoichiometric coefficients are determined.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 479-484 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Extracellular α-galactosidase from Aspergillus niger was purified 128-fold over the crude extract by gel filtration, ion exchange chromatography and chromatofocusing. Certain substrates and end products affected enzyme activity. Among the former p-nitrophenyl-α-galactopyranoside (PNPG) inhibited the enzyme at 1.4 mM while melibiose did not inhibit α-galactosidase at concentrations up to 50 mM. Enzymic end products such as glucose did not inhibit the enzyme at concentrations up to 100 mM while galactose exhibited a competitive inhibition with a Ki = 1.29 mM. The kinetic characteristics of the enzyme compared favourably to other microbial α-galactosidases and make it suitable for food process applications.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 485-494 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The separation and purification method of extracellular cellobiase and aryl-β-glucosidase from Trichoderma reesei by means of affinity chromatography on controlled porosity glass activated by ι-aminopropyltriethoxysilane and oxiranes are described.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 500-500 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: An existing HPLC-method for the analysis of stevioside from Stevia rebaudiana plants was adapted to analyse plant cell culture material. A new extraction method with methanol was developed. Exhaustive extraction of many samples (10 with our apparatus) can be done simultaneously. The quality of extraction is better than soxhlet extraction because the cold methanol was used. Samples with low stevioside content can be prepared with minimal loss. Substances which interfere with stevioside in HPLC analysis using UV detection are common in plant cell culture samples and hence need a special technique of elimination. This was accomplished by TLC-purification of the samples.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Cell cultures of Stevia rebaudiana in general do not contain stevioside when grown on their basal nutrient medium. No stable and prolonged stevioside accumulation was achieved by varying the medium components. However, in some cases a transient state was observed where more stevioside was synthesized than catabolized. The dynamic behaviour of product synthesis which led to accumulation of stevioside during only a short period was demonstrated. For accurate determination of very small amounts of stevioside, a combined TLC-HPLC method was used [1].
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991) 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 520-520 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 57-62 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The occurence of multiple forms of alcohol dehydrogenase (ADH) in methylotrophic yeasts is known from the literture. But no systematic work has been done to characterize these enzymes in detail. The aim of this work was to establish a suitable electrophoretic method for visualization of the ADH-patterns of these organisms. It was found that the recovery of the enzyme activity during polyacrylamide gel electrophoresis (PAGE) depends on the composition of the gel buffer. The ADH of five different methylotrophic yeasts from the genera Candida, Pichia and Hansenula were analyzed. Every investigated organism shows rather complex ADH-patterns.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 72-72 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 429-438 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Micro-organisms have often been considered for the production of oils and fats as an alternative to agricultural commodities. However, with the continuing low cost of agricultural production of oil-seeds, biotechnology has little to offer in the way of competition against such items as soybean oil, groundnut oil, and even polyunsaturated oil such as sunflower oil even though good facsimiles of these oils could be produced. It is now clear that if we are to use microorganisms to produce lipids, i.e. Single Cell Oil, then these must be highly specific ones which are currently expensive to obtain from agricultural sources. In particular, the possible production of a cocoa-butter substitute using mutated yeast cells is reviewed here as well as the production of highly polyunsaturated fatty acids (PUFAs) using various species of mould. With regard to producing a cocoa-butter equivalent fat, it is necessary to identify not only a cheap carbon source on which the yeast may grow (this is now considered likely to be lactose arising from whey) as well as deriving a mutant strain of the yeast which will accumulate large amounts of stearic acid within the oil. The recent work carried out in The Netherlands and New Zealand to achieve these goals is described. With regard to polyunsaturated fatty acid production, various prospects exist and indeed, the commercial production of one acid, gamma-linolenic acid, is now being produced commercially in both the U.K. and Japan. The background work leading to this product is described and opportunities for other PUFAs being produced biotechnologically are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gibberellin A3 fed to cell suspension cultures of Stevia rebaudiana showed a fast conversion to stevioside. The product was detected within one day after gibberellin addition and achieved its maximum concentration after one week. However, using special production media (without precursor or elicitor), stevioside was produced only two to seven weeks after inoculation [1]. Elicitation of suspension cultures was performed with Stevia specific and non-specific fungi and with yeast extract. Although production of some secondary metabolites was induced, stevioside was not synthesized.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Six different variations of the extraction procedure applied to yeast cells of Saccharomyces cerevisiae and Candida utilis to optimize the production of yeast extract and isolation of nucleic acids were compared. The autolysis of C. utilis at 50 to 52°C without adding chemical agents was found to be the best for the production of yeast extract. The most suitable procedures used for the extraction of nucleic acids were those which were carried out from C. utilis at pH 7.5 (92°C) and the other with 0.4 M NH4OH (40°C). Both these modifications yielded the highest amounts of polymer nucleic acids. Applying all procedures compared to S. cerevisiae an increased content of sterols (including Δ5.7-sterols, predominantly ergosterol) was detected.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 553-558 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: A 1.5-1 minifermenter consisting of RASOTHERM glass on the basis of the airlift principle was constructed and tested in the Institute of Biotechnology.The development of this fermenter bridged the gap between shake flasks and lab-scale fermenters and provided a possibility for the continuous cultivation of extremely halophilic bacteria. It was demonstrated that the fermenter can be used for cultivating bacteria that are sensitive to shear stress. It can also be recommended for purposes of cultivation of plant and animal cells because of this advantage and the possibility of this fermenter to be sterilized.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 559-570 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biotransformations represent a useful tool for the production of various chemical compounds because of their main advantages: attack of non-activated positions, regio, stereo and enantio-selectivity, and the mild reaction conditions.Organic chemistry can use these advantages in various enzymatic type reactions.One of the most interesting and promising groups of these biotransformations are the various oxidative reactions.The following article intends to give a short insight in the present state of this part of the broad field of biotransformations.Examples of technically interesting processes, preferably results of newer developments, should illustrate athe variety of enzymatical oxidative reactions used.bthe various structures of educts for aimed oxidative modifications and.cthe application in the pharmaceutical, food and chemical industries.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fermentative production by the fungus Aspergillus niger is the world's exclusive source of citric acid to be used for the food, pharmaceutical and detergents' industry. The extraordinary high yields and the delicate nutrient requirements of this process have attracted numerous investigations on its mechanism. This review highlights recent results on the regulation of its biosynthesis, emphazising especially (a) the role of pH, (b) the role of type and concentration of the carbon source, and (c) the role of anaplerotic carbon dioxide fixation in the accumulation of citric acid.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The protein enrichment of sugar cane by solid state fermentation employing Aspergillus niger was optimized in a packed bed column using a two Factor Central Composit Design α = 2, considering as independent factors the particles diameter corresponding to different times of grinding for a sample and the air flow rate. It was significative for the air flow rate (optimum 4.34 VKgM) and the particle diameter (optimum 0.136 cm).The average particle size distribution, shape factor, specific surface, volume-surface mean diameter, number of particles, real and apparent density and hollowness for the different times of grinding were determined, in order to characterize the samples.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of D-glucose isomerization to D-fructose by an original whole-cell immobilized biocatalyst preparation based on Streptomyces thermovulgaris (strain 127) have been studied under various process conditions, substrate concentration, particle size. Two versions of different activity were applied. For the biocatalyst of moderate activity the kinetic constants in the MICHAELIS -MENTEN equation for reversible reaction were determined. Effectiveness factors for both preparations were calculated and compared with other reported data.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 77-80 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Ethanol-induced leakage of UV-absorbing compounds from free and immobilized Saccharomyces cerevisiae cells was studied. The resistance of immobilized cells to this ethanol effect is accompanied with increased levels of phospholipids and sterols. These results suggest a positive role of whole cell immobilization in improving yeast ethanol tolerance.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991) 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 84-84 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 94-94 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 87-93 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Methanol assimilation and dissimilation pathways and ammonia assimilation pathway were investigated in four obligate methanol-utilizing bacteria through the detection of key enzymes. Both hexulose phosphate synthetase and hexulose phosphate isomerase, key enzymes of the ribulose monophosphate pathway (RMP) for methanol assimilation were detected whereas four key enzymes (hydroxy pyruvate reductase, isocitrate lyase, malyl-CoA-lyase and glyoxylate aminotransferase) that are characteristic of the serine assimilation pathway were absent. Key enzymes for the two methanol dissimilation pathways, the linear sequence enzymes formaldehyde and formate dehydrogenase and the RMP cyclic sequence enzymes glucose-6-phosphate dehydrogenase and 6-phosphate giuconate dehydrogenase were all detected. Ammonia was assimilated via the glutamate dehydrogenase pathway and not via the glutamine synthetase and glutamate synthase pathway.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Berlin : Wiley-Blackwell
    Acta Biotechnologica 11 (1991), S. 95-101 
    ISSN: 0138-4988
    Keywords: Life Sciences ; Life Sciences (general)
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Synthetic membranes are increasingly used in biotechnology. The possibilities of influencing the performance by membrane operation and changing the performance by physical modification were discussed. With cellulose-2,5-acetate membranes it was shown that the modification leads to an increase in the concentration of gibberellinic acid.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 0749-503X
    Keywords: Cytochrome c peroxidase ; hydrogen peroxide ; energetics ; yeast ; anaerobic respiration ; chemostat ; mitochondria ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Chemostat cultures of a catalase-negative mutant of Hansenula polymorpha CBS 4732 were able to decompose hydrogen peroxide at a high rate. This was apparent from experiments in which yeast was grown under carbon limitation in chemostat culture on mixtures of glucose and H2O2. The enzyme responsible for H2O2 degradation is probably the mitochondrial enzyme cytochrome c peroxidase (CCP), which was present at very high activities. This enzyme was partially purified and shown to be specific for reduced cytochrome c as an electron donor; no reaction was observed with NAD(P)H. Thus, reducing equivalents for H2O2 degradation by CCP must be provided by the respiratory chain.That H2O2 can act as an electron acceptor for reducing equivalents could be confirmed with experiments in which cells were incubated with ethanol and H2O2 in the absence of oxygen. This resulted in oxidation of ethanol to equimolar amounts of acetate.Energetic aspects of mitochondrial H2O2 decomposition via CCP and the physiological function of CCP in yeasts are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 157-165 
    ISSN: 0749-503X
    Keywords: Translation initiation ; codon usage: mRNA structure ; yeast ; lacZ fusion protein ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A set of 32 different codons were introduced in a lacZ experssion vector (pPTK400) immediately 3′ from the AUG initiation codon. Expression of the lacZ gene was determined in Saccharomyces cerevisiae by measuring the amount of β-galactosidase fusion protein using immuno-gel electrophoresis. A 5·3-fold difference in expression was found among the various constructs. It was found that there was no preference for a certain nucleotide in any position of the second codon and there was no distinct correlation between the level of tRNA corresponding to any particular second codon and expression. No correlation could be found between the local secondary structure and expression. When the overall codon usage in yeast and the codon usage in the second position of the mRNA is compared, there is no obvious significant difference in preference. This indicates that in yeast, in contrast to Escherichia coli, the codon choice at the beginning of the mRNA does not deviate from the one further downstream and is determined by the requirements for optimal translation elongation. Important determinatnts of the optimal context for an initiation codon in yeast therfore must be located mainly 5′ from this codon.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 0749-503X
    Keywords: Translation ; Saccharomyces cerevisiae ; lacZ fusion ; termination ; nonsense suppression ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A simple quantitative in vivo assay has been developed for measuring the efficiency of translation of one or other of the three termination codons, UAA, UAG and UGA in Saccharomyces cerevisiae. The assay employs a 3-phosphoglycerate kinase-β-galactosidase gene fusion, carried on a multicopy plasmid, in which the otherwise retained reading frame is distupted by one or other of the three termination codons. Termination readthrough is thus quantitated by measuring β-galactosidase in transformed strains. Using these plasmids to quantitate the endogenous levels of termination readthrough we show that readthrough of all three codons can be detected in a non-suppressor (sup+) strain of S. cerevisiae. The efficiency of this endogenous readthrough is much higher in a [psi+] strain than in a [psi-] strain with the UGA codon being the leakiest in the nucleotide context used. The utility of the assay plasmids for studying genetic modifiers of nonsense suppressors is also shown by their use to demonstrate that the cytoplasmic genetic determinant [pse+] broadens the decoding properties of a serine-inserting UAA suppressor tRNA (SUQ5) to allow it to translate the other two termination codons in the order of efficiency UAA 〉 UAG 〉 UGA.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 147-156 
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; microsomes ; cytochrome P450 ; sterol demethylase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Using cells grown in a chemostat at steady state, the levels of various components of the microsomal electron transport chain of Saccharomyces cerevisiae were examined. Cytochrome P450 haemoprotein levels measured in cells grown in medium with a dissolved oxygen concentration of 15% were induced between 10- and 20-fold over levels in cells grown in medium containing 70% dissolved oxygen concentation. An increase in the dilution rate of a culture growing in medium containing 15% dissolved oxygen resulted in an increase in the residual glucose concentration of the medium. This was paralleled by an increase in the microsomal levels of cytochrome P450. The rise could not be attributed either to increases in the concentration of ethanol in the chemostat or to an increase in the proportion of energy generated using fermentative pathways. However, this effect was not observed in cells grown in an oxygen concentration of 70%. Cytochrome b5 haemoprotein levels were also induced approximately three-fold by reducing the dissolved oxygen concentration from 70% to 15%. Changes in the medium glucose concentration from 0·03% to 1·6% (w/v) had no effect on the levels of this enzyme. Conversely, levels of cytochrome P450 NADPH reductase appeared lower in cells grown in 15% as opposed to 70% dissolved oxygen concentration. Northern slot blot analysis of total RNA extracted from chemostat-grown cells, probed with a C-14 sterol demethylase cytochrome P450 gene (cytochrome P450 LIA1), revealed a pattern of message induction which matched that of the cytochrome P450 haemoprotein, indicating that control of the levels of this enzyme was at least partially transcriptional. Qualitative examination of combined cytochrome P450 apoprotein and haemoprotein levels using Western blot analysis revealed a similar pattern of induction to that observed with Northern blotting.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 0749-503X
    Keywords: rDNA spacer probes ; rapid yeast identification ; Metschnikowia reukaufii ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: To test whether DNA probes derived from ribosomal DNA spacer sequences are suitable for rapid and species-specific yeast identification, a pilot study was undertaken. A 7·7 kb entire ribosomal DNA unit of the type strain of Metschnikowia reukaufii was isolated, cloned and mapped. A 0·65 kb BamHI-HpaI fragment containing nontranscribed spacer sequences was amplified and selected for testing as a 32P hybridization probe with total DNA from the type strains of M. reukaufii, M. pulcherrima, M. lunata, M. bicuspidata, M. australis, M. zobellii, M. krissii, five other strains identified as M. reukaufii and strains of Schizosaccharomyces pombe, Hansenula canadensis, Saccharomyces cerevisiae and Yarrowia lipolytica. The probe hybridized exclsively with DNA from the type strain and four other strains of M. reukaufii. DNA from one strain labelled M. reukaufii did not hybridize with the probe. Subsequent % G+C comparison and DNA-DNA reassociation with the type strain revealed that the non-hybridizing strain does not belong to the species M. reukaufii.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 195-209 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 229-244 
    ISSN: 0749-503X
    Keywords: Lipid-binding proteins ; Saccharomyces cerevisiae ; secretion ; secretory vesicles ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Yeast (Saccharomyces cerevisiae) cytosol was examined for the presence of calcium-dependent membrane- or lipidbinding proteins that might paly fundamental roles in membrane-associated phenomena in stimulated cells. A complex group of proteins was isolated from late log phase cultures of yeast strain YP3 on the basis of calcium-dependent association with yeast secretory vesicles isolated from the temperature-sensitive sec6-4 secretory mutant. The masses of the major proteins in this group were 32, 35, 47, 51, 55, 60, and 120 kDa. A similar group of proteins was isolated by calcium-dependent association with bovine brain lipids enriched in the predominant acidic phospholipids of the yeast secretory vesicles. The 47 kDa protein was highly purified when commerical yeast cake was used as the source of yeast cytosol. The 32 kDa and 60 kDa proteins were demonstrated to reassociate with lipids at calcium concentrations of 100 μM or higher, while no association was promoted by 2 mM-magnesium. The 47 kDa protein could be removed from lipids by reducing the calcium concentration to between 1 and 32 μM. The sequences of peptides isolated from digests of several of these proteins indicate that they are novel proteins but are insufficient to judge the possible homology of these proteins with mammalian membrane-binding proteins. The sequence data may be adequeate to permit isolation and modification of the corresponding genes in order to assess the possible funtion of this class of proteins in stimulated cells.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 0749-503X
    Keywords: Cloning genes ; toxic ; E. coli ; non-selective transformation ; co-transformation ; one-step gene disruption ; deletion ; ligation libraries ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The highly efficient yeast lithium acetate transformation protocol of Schiestl and Gietz (1989) was tested for its applicability to some of the most important need of current yeast molecular biology. The method allows efficient cloning of genes by direct transformation of gene libraries into yeast. When a random gene pool ligation reaction was transformed into yeast, the LEU2, HIS3, URA3, TRP1 and ARG4 genes were found among the primary transformations at a frequency of approximately 0·1%. The RAD4 gene, which is toxic to Escherichia coli, was also identified among the primary transformants of a ligation library at a frequency of 0·18%. Non-selective transformation using this transformation proctocol was shown to increase the frequency of gene disruption three-fold. Co-transformation showed that 30-40% of the transformation-competent cells take up more than one DNA molecule which can be used to enrich for integration and delection events 30- to 60-fold. Co-transformation was used in the construction of simultaneous double gene disruptions as well as disrupting both copies of one gene in a diploid which occurred at 2-5% the frequency of the single event.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 337-346 
    ISSN: 0749-503X
    Keywords: Yeast ; ADHI promoter ; regulation ; heterologous expression ; increased production ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Production of Bacillus amyloliquefaciens α-amylase by Saccharomyces cerevisiae using the multicopy plasmid pAAH5 and ways of improving the yields of secreted enzyme were studied. In standard non-buffered medium, α-amylase was rapidly inactivated but stabilization of the pH at 6 led to stable accumulation of α-amylase in the culture medium. Removal of 1100 bp of the upstream sequence of the ADH1 promoter present on pAAH5 resulted in delayed but increased α-amylase production: 29-fold in selective medium, two-fold in non-selective medium. With the original ADH1 promoter, accumulation of α-amylase in the medium started to level off before the cultures reached stationary phase and was very low when exponentially growing cells were transferred from glucose to ethanol. This coincided with the appearance of a mRNA larger than the α-amylase messenger. With the shortened promoter, the normal-size α-amylase mRNA was detected under all growth conditions and α-amylase was efficiently secreted into the medium also late in stationary phase and after transfer to ethanol. Highest total yields of α-amylase were obtained with the short promoter in non-selective glucose-containing medium; this may be explained by the greater final cell density obtained. However, the production of α-amylase per cell mass was higher in ethanol-containing selective medium. Seventy to eighty per cent of the α-amylase activity was secreted into the medium independent of the total amount produced.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 75
    ISSN: 0749-503X
    Keywords: Kluyveromyces lactis ; alcohol dehydrogenase ; mitochondrial import ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Four structural genes encoding isozymes of the alcohol dehydrogenase (ADH) system in the yeast Kluyveromyces lactis have been identified by hybridization to ADH2 DNA probes from Saccharomyces cerevisiae. In this paper we report on the isolation of KlADH4 and the complete sequencing of KlADH3 and KlADH4, two genes which show high homology to KlADH1, the ADH gene previously isolated in K. lactis, and to the ADH genes of S. cerevisiae. When compared with KlADH1, both KlADH3 and KlADH4 encode amino-terminal extensions which show the characteristics of the mitochondrial targeting sequences. These extensions are poorly conserved both at the nucleotide and the amino acid level. Suprisingly, the KlADH4 extension shows a higher identity at the amino acid level to the one encoded by ADH3 of S. cerevisiae than to the KlADH3 presequence. KlADH3 and KlADH4, in contrast to the ADH3 gene of S. cerevisiae, show a strong bias in the choice of codons.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 445-454 
    ISSN: 0749-503X
    Keywords: Heterologous expression ; S. cerevisiae ; α-glucosidase ; secretion ; maltose utilization ; novel promoter ; Candida tsukubaensis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The α-glucosidase gene of Candida tsukubaensis is contained within a 3·47 kb BamH1-Mlu1 fragment which, when introduced into Saccharomyces cerevisiae AH22 on a yeast-Escherichia coli shuttle vector, allows the transformants to utilize maltose as sole carbon source. Thus, the cloned gene confers a dominant selectable phenotype on transformed strains of S. cerevisiae which are otherwise unable to grow in nutrient media containing maltose, dextrin or other α-1,4-linked α-D-glucopyranosides, specifically hydrolysed by the α-glucosidase. The cloned enzyme expressed in yeast is secreted into the extracellular medium in a glycosylated form which accounts for up to 60% of the secreted protein and has a molecular size of 70-80 kilodalton (kDa). Deglycosylation of the α-glucosidase showed that the enzyme is composed of two distinct polypeptides with subunit molecular weights of 63-65 kDa (peptide 1) and 50-52 kDa (peptide 2). An increase in the level of expression of the α-glucosidase by yeast transformants in selective minimal medium was obtained by using a vector with increased copy number containing the leu2-d gene as selectable marker. The α-glucosidase gene promoter functions more effectively than the Gal1-10 promoter in directing α-glucosidase expression in S. cerevisiae. It also directs the expression of high levels of β-galactosidase activity in yeast when fused to a promoterless E. coli lacZ gene. Expression of the α-glucosidase gene under the control of its own promoter is constitutive, orientation dependent and not subject to catabolite repression.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 479-487 
    ISSN: 0749-503X
    Keywords: Pyruvate decarboxylase ; yeast ; Candida utilis ; Kluyver effect ; glycosidase ; β-glucosidase ; anaerobic sugar fermentation ; aerobiosis ; anaerobiosis ; activation ; deactivation ; catabolite repression ; enzyme induction ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The glucose-fermenting yeast, Candida utilis cannot use the β-D-glucoside, cellobiose, anaerobically, although it is able to do so aerobically. β-Glucoside transport and hydrolysis and pyruvate decarboxylase activities of this yeast were measured aerobically and anaerobically. β-Glucoside transport was five-fold faster aerobically than anaerobically, but there was no corresponding difference in β-glucosidase activity. Pyruvate decarboxylase activity varied greatly, being synthesized de novo in response to the presence of D-glucose and anaerobic conditions and about 50% deactivated on the removal of D-glucose or the addition of air. Activation and deactivation were rapidly reversible. Failure to utilize cellobiose anaerobically, in particular, and the Kluyver effect, in general, probably depends on much reduced glycolytic flux, associated under anaerobic conditions, with (i) lower transport rate, (ii) low substrate affinity of the relevant glycosidase and (iii) deactivation of pyruvate decarboxylase. So, in addition to the complex effects of oxygen, anaerobiosis and specific sugars on induction, repression and derepression, there are fine controls on pyruvate decarboxylase activity, leading to fast activation or deactivation of the enzyme.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 773-774 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 0749-503X
    Keywords: Methionine/threonine biosynthesis ; transcriptional regulation ; general amino acid control ; yeast ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Genes encoding enzymes in the threonin/methionine biosynthetic pathwa were cloned and used to investigate their transcriptional response to signals known to affect gene expression on the basis of enzyme specific-activities. Four major responses were evident: strong repression by methionine of MET3, MET5 and MET14, as previously described for MET3, MET2 and MET25; weak repression by methionine of MET6; weak stimulation by methionine but no response to threonine was seen for THR1, HOM2 and HOM3; no response to any of the signals tested, for HOM6 and MES1. In a BOR3 mutant, THR1, HOM2 and HOM3 mRNA levels were increased slightly. The stimulation of transcription by methionine for HOM2, HOM3 and THR1 is mediated by the GCN4 gene product and hence these genes are under the general amino acid control. In addition to the strong repression by methionine, MET5 is also regulated by the general control.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 0749-503X
    Keywords: Ribosomal RNA ; transcription ; enhancer ; promoter ; Saccharomyces cerevisiae ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The promoter and enhancer of the rRNA gene of Saccharomyces cerevisiae have been studied using a nuclease S1 protection assay to detect transcripts of an rRNA minigene in transformed yeast. Analysis of 5′ deletion mutants showed that DNA between - 163 bp and - 155 bp was important for promoter activity and that some DNA between - 155 bp and - 145 bp was essential. The importance of DNA far upstream from the initiation site was confirmed by showing that minigene expression was much reduced by linker scanner mutations clustered around - 148 bp, - 133 bp and - 100 bp, and was abolished by mutations clustered around - 118 bp. The enhancer for rRNA biosynthesis increased transcription from all of the five mutated promoters that were tested. The magnitude of the enhancer effects on weakly active promoters was two- to three-fold less than on the wild-type promoter. Expression of a minor transcript in a 5′ deletion to - 10 bp was substantially reduced by a mutation which altered two base pairs in the core sequence of the promoter-proximal REB1 binding site.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 757-760 
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; chromosome mapping ; nitrogen catabolic genes ; secretion genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 745-755 
    ISSN: 0749-503X
    Keywords: Fission yeast ; mating type expression ; silencer ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The fission yeast, Schizosaccharomyces pombe, expresses one of two alternative mating types. They are specified by one of two determinants (M or P) present at the mat1 locus. In addition, silent copies of M and P are present on the same chromosome. In the present work we demonstrate that the difference between the active and the silent stage of the P determinant is controlled by four repressive elements that are located at the silent locus. There are two elements to the left and two to the right of the mating type cassette. Both elements to the left and either one of the two elements to the right are required for an effective blockage of transcription. When they are combined, the four elements define a highly efficient silencer functionally similar to the HMRE and HMLE and HMLI silencers in Saccharomyces cerevisiae. In addition, the DNA surrounding the silent P locus confers symmetric partitioning in mitosis to Schizosaccharomyces pombe ars plasmids.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 775-780 
    ISSN: 0749-503X
    Keywords: Kluyveromyces ; lactic acid ; transport ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Lactic acid-grown cells of a strain of Kluyveromyces marxianus transported D-and L-lactic acid by a saturable mechanism that was partially inducible and subject to glucose repression, with the following kinetic parameters at pH 5·4: Vmax = 1·00 (±0·13) mmol h-1 per g dry weight and Ks = 0·42 (±0·08) mM. Lactic acid transport was competitively inhibited by pyruvic, glycolic, acetic and bromoacetic acids. The latter, a non-metabolizable analogue, was transiently accumulated, the extent depending on the extracellular pH. The pH dependence of the Ks values for undissociated lactic acid and for the lactate anion indicated that the latter was the transported species. Lactate uptake was not accompanied by the simulatate uptake of protons, potassium ions or sodium ions excluding symport mechanisms. Initial lactic acid uptake led to transient membrane hyperpolarization as measured with a fluorescent dye excluding also an electroneutral anion antiport mechanism. It was concluded that lactate anions use a monocarboxylate uniport and that the counter anion, possibly bicarbonate, uses a separate channel, the coupling being electrical and loose.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 1-14 
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; cell cycle ; budding ; spore germination ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cloning and sequencing of RCS1, a Saccharomyces cerevisiae gene whose product seems to be involved in timing the budding event of the cell cycle, is described. A haploid strain in which the 3′-terminal region of the chromosomal copy of the gene has been disrupted produces cells that are, on average, twice the size of cells of the parental strain. The critical size for budding in the mutant is similarly increased, and the disruption mutation is dominant in a diploid heterozygous for the RCS1 gene. Spores from this diploid have a reduced ability to germinate, the effect being more pronounced in the spores carrying the disrupted copy of RCS1. However, disrupted cells recover from α-factor treatment equally as well as wild-type cells.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 0749-503X
    Keywords: Hansenula polymorpha ; alcohol oxidase ; amine oxidase ; choline ; peroxisome-deficient mutant ; enzyme assembly ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have studied the expression of alcohol oxidase (AO) in a peroxisome-deficient mutant strain of Hansenula polymorpha. High levels of octameric, active AO (up to 3·0 U/mg protein) were detected in cells grown at low dilution rates in a glucose-limited chemostat in the presence of choline as the sole nitrogen source. Monomeric or other intermediate forms of AO were not detected in the mutant strain. This indicated that assembly of the protein into active octameric molecules in the cytosol was as efficient as in wild-type cells where this process is confined to the peroxisomal matrix. At relatively low rates of expression (less than 1 U/mg protein) AO was localized throughout the cytosol and, surprisingly, was also present inside the nucleus. However, at enhanced levels large crystalloids were formed. Generally one crystalloid was observed per cell, whereas smaller ones were occasionally found in developing buds. Also large crystalloids have been observed inside the nucleus. These crystalloids were not surrounded by a membrane. Based on the morphology of the molecules that constituted these crystalloids and the results of (immuno)cytochemical experiments we conclude that the crystalloids are composed of octameric AO molecules, arranged in a regular lattice, identical to the 3-dimensional architecture previously described for the crystalline matrix of peroxisomes in methanol-grown wild type cells of H. polymorpha. Attempts to purify the crystalloids by conventional fractionation methods failed, due to their apparent fragility; however, (immuno)cytochemical experiments revealed that catalase and dihydroxyacetone synthase were also associated with these structures.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 0749-503X
    Keywords: Spontaneous mutagenesis ; repression and derepression of genes ; environmental effects ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Spontaneous mutation of some genes was studied in haploid adenine and leucine auxotrophic yeast Saccharomyces.It was shown that a decrease in the amount of adenine (from 500 to 0 mgl-1) or leucine (from 300 to 0·3 mgl-1) in the medium, simultaneously with the transition from repression to derepression of the biosynthesis of these metabolites, resulted in a 15- to 150-fold increase in the reversion rate of genes ade2 and leu2, respectively, for different strains. At the same time the mutation rate of suppressor genes varied relatively little (up to five-fold), and that of gene lys1 did not change at all. It was also demonstrated (on gene leu2) that the mutation rate is determined by the composition of the nutrient medium at the time of the S-phase of the cell cycle and it does not depend on the cultivation conditions during the presynthetic period.We discuss the hypothesis that derepressed genes mutate with a significantly higher rate than genes in the repressed state.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 25-36 
    ISSN: 0749-503X
    Keywords: Replication ; morphogenesis ; yeast ; plasmid stability ; extrachromosomal plasmids ; Y. lipolytica. ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Previous attempts to isolate autonomously replicating sequences (ars) from the dimorphic yeast Yarrowia lipolytica have been unsuccessful. We isolated a Fil- mutant unable to produce hyphae and growing only in a yeast form to facilitate ars isolation. This mutant was transformed with a Y. lipolytica DNA bank and several unstable clones were obtained. Extrachromosomal plasmids were evidenced in yeast recovered in Escherichia coli and characterized by restriction mapping. They were able to retransform Fil- and Fil+ yeast strains at high frequency and transformants displayed a slightly unstable phenotype. The detailed analysis of the plasmids showed that only two different ars sequences had been isolated, each of them corresponding to a unique sequence in the Y. lipolytica genome. We concluded that functional ars sequences that can be cloned on plasmids are rare in this yeast.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 0749-503X
    Keywords: Ascomycetous yeasts ; ribosomal RNA ; molecular evolution ; phylogeny ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Species of the genera Saccharomyces, Schizosaccharomyces, Debaryomyces and Schwanniomyces were compared from their extent of divergence in three regions from small (18S) and large (25S) subunit ribosomal RNAs comprising a total of 900 nucleotides. With the exception of the closely related Saccharomyces bayanus and S. pastorianus, which appear to have identical sequences, all other species could be distinguished by nucleotide differences in a variable region of the large subunit, and genus-specific nucleotides were discernible in all three regions. The taxon D. tamarii differed markedly from other species and is excluded from Debaryomyces. By contrast, Schwanniomyces occidentalis showed few nucleotide differences with Debaryomyces spp. and its transfer to Debaryomyces is proposed. Schizosaccharomyces proved to be somewhat more divergent than Saccharomyces and Debaryomyces, but species differences appear insufficient for dividing the genus. Some of the factors influencing estimates of phylogenetic distances from rRNA sequences are discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 0749-503X
    Keywords: Nuclear proteins ; HMG proteins ; yeast ; Saccharomyces cerevisiae ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In order to determine the biological functions of moderately abundant, high mobility group (HMG)-like nuclear proteins, a genetic approach has been taken. The gene for one such protein, NHP2, has been cloned and characterized from Saccharomyces cerevisiae. NHP2 has been called ‘HMG-like’ because of the physical/chemical properties it shares with the HMG proteins from higher eukaryotic cells. However, nucleotide sequence analysis revealed that NHP2 could encode a 17·1 kilodalton basic protein which was not significantly homologous to any previously sequenced HMG proteins. Thus NHP2 defines a new member of the HMG class of proteins. A search of protein databases showed that the amino acid sequence of NHP2 shared significant identities with two ribosomal proteins; the acidic ribosomal protein S6 from Halobacterium marismorium and protein L7a from mammals. The biological relevance of these homologies is nuclear since previous biochemical results indicated that NHP2 was not a ribosomal protein. S1 nuclease analysis indicated that the gene contained no introns but had multiple transcription initiation sites 20 to 40 bases before the ATG codon. Finally, NHP2 has been shown to have a critical role in the cell; when a diploid yeast strain deleted of one copy of the NHP2 gene was sporulated and dissected, only half of the spores grew into normal colonies. The rest of the spors germinated, but only formed microcolonies containing 12 to 40 cells. None of the spores which grew into normal-sized colonies contained the mutant NHP2 gene, thus demonstrating that the NHP2 protein has an essential physiological function.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 0749-503X
    Keywords: Metallothionein ; resistance to metal ions ; expression vectors ; CUP1 ; β-galactosidase ; upstream activation sequences ; recombinant DNA ; yeast ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Shuttle plasmids, pE1.CUP1B and pE1.CUP1E of 10·6 kb, have been constructed between the metallothioneinencoding CUP1 gene of Saccharomyces cerevisiae and a vector capable of replication in Kluyveromyces lactis. Introduction of these plasmids into K. lactis confers resistance to copper as well as to cadmium and silver. Resistance to these latter metal ions, in the absence of induction by copper, suggested that the CUP1 gene is constitutively expressed in the foreign background. Introduction of the lacZ reporter gene from Escherichia coli into a cloning site downstream from the CUP1 promoter showed that expression of this gene is constitutive in K. lactis but in S. cerevisiae induction by copper is necessary. Sequences upstream from the CUP1 promoter are involved in the constitutive expression since deletion of 91 nucleotides from this region abolishes metal resistance. It is suggested that a K. lactis protein, normally involved in activating transcription of the resident CUP1 gene in the presence of copper, can promote transcription in the absence of metal ion by binding to the upstream activation sequence of the introduced CUP1 gene.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; yeast ; starch ; secretion ; extracellular glucoamylase ; feed-back control ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three modes of production of the extracellular glucoamylase (GA) in Saccharomyces cerevisiae have been identified: repressed, basal and induced. The repressed mode is found with cells grown in rich media containing non-limiting concentrations of monosaccharides or disaccharides, including GA-hydrolysable maltose, as a sole carbon source. Both the basal and the induced modes (spanned by some seven-fold difference in the rate of GA production) can be displayed by either glucose-limited or glycerol- plus ethanol-consuming cultures: the induced mode is switched over to the basal one due to a feed-back inhibition by extracellularly accumulated GA. It is proposed that the feed-back control involved in GA production can be attenuated by starch which can thus ‘induce’ higher rates of GA production compared to the basal mode.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 211-217 
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; cell wall mutant ; endocytosis ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The VY1160 mutant is characterized by cell lysis in hypotonic solutions and generally increased permeability to substances for which Saccharomyces cerevisiae cells are not permeable. Two mutations, srb1 and ts1, have been identified in VY1160 mutant, and previous studies (Kozhina et al., 1979) have shown srb1 to be responsible for cell lysis. We now present evidence that the ts1 mutation leads to increased endocytosis in VY1160 cells. The internalization of lucifer yellow carbohydrazide in VY1160 cells is time-, temperature- and energy-dependent an consistent with a fluid-phase mechanism of endocytosis. The rate of steady-state accumulation of hte dye at 37°C is 145 ng/μg DNA per h for VY1160 mutant and 23 ng/μg DNA per h for S288C parental strain. Studies with isogenic strains having either the srb1 or the ts1 mutation, or SRB1 TS1 wild-type alleles have shown that only ts1 strains possess increased endocytosis. Quantitation of endocytosis in cells grown at 24°C and shifted at 38°C shows that ts1 strains, but not srb1 and wild-type strains, increase ten-fold the internalization of lucifer yellow 2 h after the shift at 38°C. The analysis of ts1 × wild-type crosses provides evidence that the temperature-sensitive phenotype segregates together with the enhanced endocytosis. It is concluded that the increased endocytosis might the generally increased permeability of VY1160 mutant cells.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 7 (1991), S. 245-252 
    ISSN: 0749-503X
    Keywords: K. lactis ; killer system ; ORF 10 ; DNA binding protein ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: ORF 10 of the K2 plasmid from Kluyveromyces lactis encodes a small basic protein (22·3% lysine). The function of its product has been investigated. Western blot analysis, using an antibody against MS2 RNA polymeras/ORF 10 fusion protein, reveals a protein band with an apparent molecular weight of 14 kDa. The protein can bind a DNA-Sepharose column, and is eluted by 350 mM-salt. Immunoprecipitation experiments show that the ORF 10 protein coprecipitates with the linear genomic DNAs of the two killer plasmids (K1 and K2). From Western/Southern blot data, it is possible to conclude that the interaction between protein and DNA occurs directly, rather than via other proteins(s). ORF 10 is easily detected by Western blot and its transcript is one of the most abundant of the K2 plasmid, suggesting that this protein may have a structural rather than a regulatory function. This possibility is also suggested by the observed sequeence homology between the ORF 10 protein and the family of histone-like proteins.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 0749-503X
    Keywords: Yeast ; Chromosome III ; sequence ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have entirely sequenced YCR59, which is a 10·1 kb segment of the right arm of chromosome III, and is a part of the clone E5F from the Newlon collection. The segment contains two long open reading frames (ORFs): YCR591 which starts in the adjacent fragment H9G (situated towards CRY1 and the centromere), and continues with 1833 codons in YCR59. The second ORF YCR592 is 1226 codons long and encoded entirely within YCR59. The two ORFs represent 91% of the total length of the segment. Excellent agreement in both location and length is found between the ORFs YCR591 and YCR592 and the transcripts 86 and 87 respectively in the Yoshikawa and Isono (1990) map of chromosome III. The two ORFs correspond to new genes and show no significant similarity with any known genes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 0749-503X
    Keywords: Secretion ; methylotrophic yeast ; glycosylation ; methanol oxidase ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The methylotrophic yeast Hansenula polymorpha, a host organism for the production of heterologous proteins, has been applied to produce the α-galactosidase from the plant Cyamopsis tetragonoloba (guar). The yeast/Escherichia coli shuttle expression vector used is based on the origin of replication of the endogenous 2 μm plasmid of Saccharomyces cerevisiae and the LEU2 gene of S. cerevisiae for selection in H. polymorpha. In the expression vector, the α-galactosidase is controlled by the methanol-regulated promoter from the methanol oxidase gene, MOX, of H. polymorpha. The signal sequence of SUC2 (invertase) from the yeast S. cerevisiae, was used to ensure secretion of the α-galactosidase enzyme. After transformation and stabilization, the expression vector was stably integrated in the genome. The active α-galactosidase enzyme was efficiently secreted (〉85%) and after methanol induction, the expression level was 42 mg/l. Amino-terminal sequencing of the purified α-galactosidase enzyme synthesized by H. polymorpha showed that the S. cerevisiae invertase signal sequence was correctly processed by H. polymorpha. The secreted α-galactosidase was glycosylated and had a sugar content of 9·5%. The specific activity of the α-galactosidase produced by H. polymorpha was 38 U mg-1 compared to 100 U mg-1 for guar α-galactosidase. Deglycosylation of the H. polymorpha α-galactosidase restored the specific activity completely.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...