摘要:

AbstractThe present study emphasizes the effects of different qualities of visible light, intensities of white light, temperature and pH on the sporulation in the green algaPithophora oedogonia(MONT.) WITTROCK. Of the different qualities of light used, green light was found to delay the initiation of sporulation. Percentage of sporulation was greatly decreased in yellow light followed by red light. Delay in time taken for initiation of sporulation and decrease in percentage sporulation were observed at 0.25 and 0.5 K lux intensity of white light. Sporulation upto the extent of its natural population was achieved with white light between 2 to 3.5 K lux, temperature between 20 to 30 °C and pH between 4

ISSN:0044-2208    

DOI:10.1002/jobm.19830230602

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractPhenotypically different submerged mycelium conserves had been produced from a spore conserve of the HP‐strainStreptomyces griseusand proofed in a product formation culture as a test system.The phenotypical characters induced on the base of the genotype proved in a cultivation cycle during 30–34 reduplications of the biomass constant.Employing the HP phenotype we investigated the possibility of economizing the substrate turnover by utilizing the anabolic potential for the synthesis of secondary substances and/or reducing the conservation catabolism during the stationary growth stage. As criteria for that served the stoichiometric turnover equation of the streptomycin biosynthesis and the quotientqO2/qGluctaking at full substrate oxidation the numerical value 6.During the stationary growth stage the relation of maintenance anabolism to maintenance catabolism in addition to the formation as secondary substances is not fixed in the tested HP phenotypes, but in a striking manner variable. The relation of by‐product synthesis to secondary metabolism synthesis, too, is variable in the stationary growth stage with constant maintenance catabolism. Due to those response reactions on phenotypical manipulations an economization of the substrate turnover during the product formation stage with stationary growth is not possible in the streptomycin producerStreptomyces gr

ISSN:0044-2208    

DOI:10.1002/jobm.19830230603

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractZero time addition of the autoregulator (L‐factor) fromS. griseus(Lkm+Amy+) to surface cultures of its bald mutant ZIMET 43682 (Amy−Lkm−) restored the capacity to form both anthracycline‐type antibiotic leukaemomycin and aerial mycelium. The pertinent mycelia displayed the same growth rate and cellular levels of nucleic acid as the asporogeneous phenotype but the composition of fatty acids and phospholipids as well as the ratio of cytochromesbandcwere altered. These differences indicate alterations in the cellular architecture of substrate and aerial hyphae. The result suggest that the autoregulator triggers the onset of a complex programme of differentiation at a very earl

ISSN:0044-2208    

DOI:10.1002/jobm.19830230604

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19830230605

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractTheE. colistrains CP78 and CP79 carrying the plasmidpBR 322display similar growth kinetics in discontinuous culture. During limitation of amino acids the stringent strain CP78 is able to synthesize guanosine‐5′ diphosphate‐3′‐diphosphate (ppGpp) and guanosine‐5′‐triphosphate‐3′diphosphate, but the relaxed strain can not produce highly phosphorylated guanosine nucleotides. During the logarithmic phase of growth both strains contain similar amounts of plasmid DNA. During amino acid starvation plasmid DNA is amplified in the relaxed strain only, whereas in the stringent strain the plasmid content per cell remains constant.In stationary phase cells of CP78 a higher activity of plasmid‐coded β‐lactamase than in CP79 cells was detected. Furthermore, remarkable differences between both strains were observed in the composition of proteins derived from the periplasmic fraction and separated by polyacrylamide gel electrophoresis.Our results might indicate a negative control ofpBR 322DNA replication by ppGpp duri

ISSN:0044-2208    

DOI:10.1002/jobm.19830230606

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe simultaneous utilization of methanol and glucose byHansenula polymorphaMH20 was investigated in chemostat (C‐limited) cultivation. The mixed‐substrate utilization results in biomass yields which are greater up to 20 to 25% as expected assuming an additive growth on both substrates. This is referred to as an auxiliary‐substrate effect. Additionally, methanol can be utilized at higher growth rates in the presence of glucose compared to those obtained on this substrate alone. The extend of the auxiliary‐substrate effect and the optimum ratio of substrates to reach this effect depend on dilution rate. The greatest stimulation in yield is obtained atD∼ 0.1 h−1, after raising the dilution rate this effect diminishes. At a rate of 0.1 h−1the optimum mixed‐substrate ratio of methanol: glucose is 7: 1(g). By increasing the growth rate the ratio changes toward glucose and reached a value of 1:1 (g) atD= 0.3 h−1. This change in the optimum ratio correlates with diminution in yield coefficient of methanolp accomanying an increase in growth rate>0.15 h−1. Energy balances of the utilization of the single substrates are used for interpretation of these results. From this it is evident that methanol does not play the role of an energy‐rich substrate in the metabolism of yeast. Rather glucose is the energy‐providing substr

ISSN:0044-2208    

DOI:10.1002/jobm.19830230607

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractNalidixic acid induces segregation of auxotrophs from prototrophic hybrids ofCandida albicansartifically produced by fusing complementing auxotrophic protoplasts. The auxotrophies recovered are limited to those introduced through the fusion process, and patterns of segregations for linked auxotrophic markers demonstrate the segregants are products mitotic cossing‐over. Nalidixic acid does not induce auxotrophies of any sort in clinical isolates ofC. albicans.These findings are contrary to a current hypothesis that natural strains ofC. albicansare diploid and heterozygous for a variety of auxotrophic mutation

ISSN:0044-2208    

DOI:10.1002/jobm.19830230608

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19830230609

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractMore than 30 conjugative R plasmids between 60 and 70 Md in size were identified in wild type strains ofEnterobacteriaceaeisolated in German Democratic Republic, Bulgaria, Mongolia, Poland, Ethiopia, Iraque, and Soviet Union. They have been characterized by means of several genetic and molecular techniques as members of a new incompatibility group, termed IncZ. The properties of these plasmids including digestion pattern after EcoRI treatment demonstrate a phylogenetic relatedness.

ISSN:0044-2208    

DOI:10.1002/jobm.19830230610

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19830230612

出版商:Akademie‐Verlag    

年代:1983

数据来源: WILEY