摘要:

AbstractA mathematical model with three modifications was stated, which describes the diauxic growth ofSaccharomyces cerevisiaeon aerobic conditions in a glucose‐limited medium. The model was investigated by means of an analogcomputer. The first and simplest modification of the model is based on a well‐known growth model and includes an additional team for catabolic respression. This 1st model could be fitted without complications to the experimental data of a batch culture, which shows growth, consumption of glucose, and production of ethanol during a first log‐phase and growth and consumption of ethanol during a second log‐phase. Complementation with the terms necessary for continuous culture conditions gives the 2nd model and, therefore, the possibility to predict the properties of the corresponding continuous culture. The prediction agrees qualitatively with the experimental data. After consideration of additional factors as the inhibition of growth and ethanol production by ethanol a 3rd model allowed to fit the experimental data of a continuous

ISSN:0044-2208    

DOI:10.1002/jobm.19720120802

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe migration of oil in sediments and the accumulation in oil traps is still a problem not yet solved. After BAKER, KENNEDY and others, hydrocarbons may be solubilized by natural surfactants,i.e.salts (soaps) of fatty acids or naphthenic acids, and migrate in an emulsified stage or in micellar distribution. Accumulation in a trap is inaugurated by separation of the components. In a model experiment with columns filled with sand, we succeeded herewith in a system of paraffine oil, solubilized by sodium palmitate, and an enrichment of denitrifying bacteria adapted to palmitinic acid as a carbon source. Gas production in the sand was visible already the second day. Almost 99% of the hydrocarbons were entrapped in the sand after 30 days by the activity of the denitrifiers while in the control experiment, about 50% migrated through the column and the rest was filtered off nearly unchanged by the sand.

ISSN:0044-2208    

DOI:10.1002/jobm.19720120803

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractEs wird die durchR‐Plasmide verursachte Konjugationsfähigkeit von 20S. typhimurium‐Stämmen im Vergleich zuKlebsiella pneumoniaeundS. heidelbergermittelt. Im Durch‐schnitt lagen die Übertragungsfrequenzen mitS. typhimuriumdeutlich unter denen mitKl. pneumoniaeundS. heidelberg.Jedoch wurden auch Ausnahmen beobachtet, aus denen sich die Bedeutung des Donators für die jeweilige Übertragungsfrequenz ergibt. Donatoren, die nebenR‐Plasmiden auch eine Nifurantin‐ bzw. Nalidixinsäureresistenz besaßen, konnten zwar dasR‐Plasmid, nicht aber die Nifurantin‐ bzw. Nalidixinsäureresistenz aufS.

ISSN:0044-2208    

DOI:10.1002/jobm.19720120804

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractOnly one fungus species develops in the fungus gardens of the leaf‐cutting antAtta insularisin Cuba under the influence of the ants. This species equals the fungus described by MÖLLER and forms the characteristic ‘kohlrabi bodies’ composed of bromatia. The supposed perfect fructification‘Rozites’ gongylophoraMÖLLER, was not found. With regard of the very rare appearance of that basidiomycete and of the dubious generic position of it, the bromatia‐forming mycelium is described under the new nameAttamyces bromatificus (Mycelia sterilia). In pure culture,Attamyces bromatificusdoes not form reproductive structures. In nature, probably, propagation of this fungus depends almost on the activity of the leaf‐cutting ants. Therefore, the fungus must be considered as a specialized ectosymbiontAttamyces bromatificusforms bromatia also in pure culture. Consequently, bromatia are not formed as a reaction to direct influence (by bite of by moistening with saliva) of antsIf the ants are eliminated from the fungus garden, in unsterile conditions,Attamyces bromatificussuccumbs rapidly to the competition of unspecific soil fungi. Among others, a rapidly growing imperfect fungus, which represents a new genus and species described asPhialocladus zsoltii, develops frequently within 2–3 days; it corresponds to the ‘strong conidial form ofRozites gongylophora’illustrated by MÖLLER and others. Simultaneously with the substitution ofAttamyceby contaminants, the pH of the fungus substrate

ISSN:0044-2208    

DOI:10.1002/jobm.19720120805

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractFive species of myxobacteria have been found to fruit more or less frequently on dung pellets of rabbits, hares, and roes collected in the surroundings of Karlsruhe, West‐Germany. The most common species,Myxococcus fulvus, was followed byM. virescensandChondrococcus coralloideswhich occurred pretty abundantly, too. Now and again fruiting bodies ofArchangium gephyraandPolyangium fuscumcould be observed, in the case ofP. fuscumconfined to certain substrates. Other species have been rareAnalysing the distribution of these five relatively common species from dung pellets and soils, differences in the frequency of occurrence were demonstrated when the rather complex substrate of soil is differentiated in the upper horizon of soil without roots, and the rhizosphere of flowering plants and mosses.M. fulvus, Ch. corralloides, andA. gephyramay be regarded as to be more or less ubiquitous species. In some cases,M. fulvusandCh. coralloidesappeared to be rhizophilic. On the other side,P. fuscumcould only be observed in soils and avoided the rhizosphere.M. virescenswas found only onceConditions for microbial life in the rhizoidosphere of bryophytes growing on rocks can be regarded in a modified sense as such in soils in the first steps of their development. Among the fruiting myxobacteria it resulted that in addition toM. fulvus, M. virescens. Ch. coralloides, andA. gephyra, Podangium lichenicolumoccurred quite frequently, whereasPolyangium fuscumcould not be observed. In well‐developed soils, however,Podangium lichenicolumwas missing, andPolyangium fuscumwas found frequen

ISSN:0044-2208    

DOI:10.1002/jobm.19720120806

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractUntersuchungen haben ergeben, daß eine Manganoxydation bei Pilzen meist nur in Gegenwart geringer Mengen von organischer Substanz stattfindet. Hierbei ist es gleichgültig, ob die organische Substanz als Pepton, Casamino acids oder Zucker gegeben wird. Zu hohe Mn++‐Konzentrationen (über 10–50 mg/l) haben überwiegend negativen Effekt auf die Bildung von Trockensubstanz. Eine deutliche Manganoxydation findet unter annähend autotrophen Bedingungen nicht statt; unter heterotrophen, nährstoffarmen Bedingungen wird in Gegenwart und bei Oxydation von Mn++die Bildung von Myceltrockengewicht gefördert. Die Ergebnisse werden im Hinblick auf die Existenz vonMetallogenium symbioticum

ISSN:0044-2208    

DOI:10.1002/jobm.19720120807

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractCell wall growth of an asynchronous culture ofSchizosaccharomyces pombewas studied by fluorescence microscopy and time‐lapse cinematography. The cell wall growth of individual cells is a time‐ordered process which can be divided into 4 stages: post‐division stage, stage of growth initiation, stage of extension growth, and constant length stage. Different aspects of these stages are discussed. During the exponential phase of growth the population has a rather stable structure from the point of view of division scar numbers. The significance of the division scars for the study of cell wall growth and multiplication is disc

ISSN:0044-2208    

DOI:10.1002/jobm.19720120808

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractA study has been made of changes in cell walls and ultrastructure of cells and regenerating protoplasts ofSchizosaccharomyces pombegrown in different concentrations of 2‐deoxyglucose (2DG). At concentrations of 0.1% and higher the inhibitor reversibly blocked growth of cells and protoplasts and completely inhibited cell wall synthesis. Concentrations of 0.05% and lower allowed protoplasts to grow and induced early or late lysis in normal cells. On the surface of protoplasts only the fibrillar component was formed; secretion of the soluble fraction ceased. The early lysis of the cells was a result of degradation of cell wall material at growing sites (concentration of 2DG 0.02–0.05%), the late lysis occurred in cells with weakened growing regions, where aberrant material was deposited (concentrations 0.01–0.02%). Concentrations of 2DG below 0.01% did not affect the growth of the cells or the reversion of protoplasts to normal cells. 2DG was not incorporated into the walls of cells or regenerating protoplasts, and did not influence the ultrastructure of cells or protoplasts except for the effects on the cell

ISSN:0044-2208    

DOI:10.1002/jobm.19720120809

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19720120812

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19720120814

出版商:Akademie‐Verlag    

年代:1972

数据来源: WILEY