摘要:

AbstractEs wird der Gehalt der freien, mit 80%igem Äthanol extrahierbaren Aminosäuren unter besonderer Berücksichtigung des Prolins mittels automatischer Analyse bestimmt und seine Beziehung zur Synthese der Tripeptidseitenkette der Peptidalkaloide vonClaviceps purpureadiskutiert.Wie Versuche mit den Stämmen pepty 695 („Produzent”︁) und pur 221 („Nichtproduzent”︁) bei saprophytischer Kultur auf den Nährlösungen 720 („Produktionsmedium”︁) und M 10 („Nicht‐produktionsmedium”︁) zeigen, sind in Abhängigkeit von der Kulturdauer (1 bis 13 Tage) für die Differenzen im Aminosäuremuster eher Milieubedingungen als Stammspezifika verantwortlich. Mengenmäßig treten die Aminosäuren Ala, γ‐Abu, Glu, Asp, Arg, Lys, Pro und die Säureamide Gln und Asn hervor. Try konnte nicht nachgewiesen werden. In beiden Stämmen wird bei Kultur auf NL 720 Arg zu Kulturende akkumuliert. Der „Nichtproduzent”︁ pur 221 zeichnet sich durch hohe Prolinmengen aus. Unter den gewählten Bedingungen hat der Pr

ISSN:0044-2208    

DOI:10.1002/jobm.19780180402

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA bacterium isolated from Burdwan (India) soil was found to accumulate l‐valine in the growth medium and identified to be a strain ofBacillus subtilis.The strain is able to grow and accumulate valine in a purely synthetic medium, but supplementation of the synthetic medium with either Casamino acids or yeast extract or with both, significantly improves the yield. The entire fermentation period can be divided into a growth phase and a production phase, which can be prolonged by adjustment of pH to the neutral range. Among the different carbon and nitrogen sources tested glucose at 8.5% and l‐glutamic acid at 0.8%, respectively, were found most suitable. Cane sugar molasses tested as a substitute for glucose significantly stimulated growth but valine production was less. Different vitamins tested stimulated growth and valine yield and an inoculum level of 10% (v/v) of the medium was found to be optimal. The yield of valine under optimal conditions was found to be 4.53 g per litre of the medium. Valine has been isolated in crystalline form from the fermented broth by ion exchange resin chromatography and found to be a pure sample of the l‐i

ISSN:0044-2208    

DOI:10.1002/jobm.19780180403

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA phenomenological and a more causal model are developed for the multiphasic discontinuous growth. The first model distinguished between the lag‐phase, the exponential phase, the transient phase from the exponential to the linear phase, the linear phase, the transient phase from the linear to the stationary phase, and the stationary phase. The parameters are rate constants, critical values of biomass, and time constants. The parameters are estimated for experimental data of growth ofCandida lipolyticaunder limitation of thiamine (MÜLLERet al.1978).These data are fitted also by a more causal model. This second model is in agreement with Monod's idea that a linear growth phase may be due to an enzyme or enzyme system which has a constant activity. In the analysed case of limitation of thiamine the constancy of the dehydrogenase activity is caused by a constant level of the coenzymethiaminepyrophosphate. Thus, when such a thiamine requiring enzymatic step becomes to the „bottle‐neck”︁, bacterial culture switches over from exponential to linear growth. The end of linear phase is discussed more hypothetically by the high cooperativity of activity of dehydrogenases and the existence of a minimal specific growth rate.The results of modeling and parameter estimation are compared with experimental data ofC. lipolytica.These two models are able to interpret the growth kinetic of these multipha

ISSN:0044-2208    

DOI:10.1002/jobm.19780180404

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractLa présence d'une α amylase pariétale dePichia burtoniiBOIDINest étudiée. Deux formes ont été trouvées. Une fraction facilement extractible au moyen d'un tampon phosphate 20 mM et une fraction fortement liée à la paroi. Le pH optimum est 6,2.L'activité enzymatique n'est pas modifiée par les ions K+, Na+, NH4+. Elle est fortement inhibée par EDTA et les m

ISSN:0044-2208    

DOI:10.1002/jobm.19780180405

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractMass formation of petite mutants took place in a strain ofSaccharomyces cerevisiaewhen grown at superoptimal temperatures. After an initial period of exponential growth, a second period followed during which exponential death and net exponential petite mutation concurred with exponential growth. The specific rates of the three exponential processes were of the same order of magnitude and varied with the temperature. Net exponential petite mutation did not occur during the deathless first period of growth at superoptimal temperatures nor at any time during growth at suboptimal temperatures. Mitochondria are discussed as possible targets of thermal death in mesophilic yeasts.

ISSN:0044-2208    

DOI:10.1002/jobm.19780180406

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCells between two intercalary heterocysts differentiate at random into spores inA. circinalis. One or more cells, which fail to transform into spores, are present between the two adjacent spores, and these cells disorganize later. A critical C:N ratio regulates sporulation and heterocyst formation. During sporulation the reductive ability of the heterocyst gradually diminishes.It is concluded on the basis of this and other evidence that sporulation is regulated by interactions between heterocysts and vegetative cells which are manifested in diverse patterns in different species of blue‐green alga

ISSN:0044-2208    

DOI:10.1002/jobm.19780180407

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe effects of oxygen on 29 strains of „strictly anaerobic„ bacteria, which are often found in human intestinal tracts, were studied. The initiation and rate of growth, together with the maximum extent of growth, in sealed L‐shaped tubes containing a medium through which a gas mixture containing 5% O2had been bubbled were compared with those under anaerobic conditions. On the basis of the results, these anaerobic bacteria could be divided into three general types: Type A; strains which grew in almost the same way as under anaerobic conditions, type B; strains which grew less well than under anaerobic conditions, and type C; strains incapable of growth initiation in the initial presence of the dissolved O2. After the experiments no residual O2was found in the medium of type A strains. The decrease in O2concentration was small, if any, in media of type B and C strains.Using representative examples of these three types, physical changes in the culture medium accompanying growth were observed in a stirred fermenter equipped with three electrodes; Eh, oxygen, and pH. The results were as follows: Type A: Growth ofVeillonella alcalescensin the fermenter started after the complete comsumption of dissolved oxygen and when Eh had dropped below ‐ 300 mV. A slight drop in pH occurred in parallel with the growth. Type B: In the culture ofBifidobacterium adolescentis, growth was simultaneous with the changes in O2concentration, Eh, and pH. Type C: Growth ofBacteroides vulgatuswas not initiated in the presence of the dissolved O2. Little change in O2concentration, Eh or pH was observed.When bacterial cells which had grown in the medium initially containing dissolved O2were subjected to serial transfer to similar fresh media, growth activity appeared to decrease progre

ISSN:0044-2208    

DOI:10.1002/jobm.19780180408

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractDie im Screening‐Programm eingesetzten Enzymsubstrate wurden ausgewählt auf Grund der Erfahrungen, wonach eine Reihe α‐l‐Arabinofuranoside cytotoxischer Phenole synthetisiert werden konnten, die wesentlich ungiftiger als die entsprechenden Aglykone sind (ARNDTu.GRAFFI1975,ARNDTY et al. 1976). Hinzu kommt, daß esSCHWABEet al.(1976) gelungen ist, ein relativ unwirksames α‐l‐Arabinofuranosid der cytotoxischen Substanz β‐Peltatin A zu synthetisieren. Im Screening‐Programm untersuchte Vertreter derActinomycetaleswurden der IMET‐Stammsammlung des Zentralinstituts für Mikrobiologie und experimentelle Therapie, Jena‐DDR, entnommen bzw. frisch aus Erdproben isoliert. Die Vorzucht der Mikroorganismen erfolgte für die Dauer von 2 Tagen bei 28 °C auf Schütteltischen in einem Flüssig‐Medium folgender Zusammensetzung: 1,5% Sojamehl, 1,5% Glucose, 0,1% CaCO3, 0,5% NaCl in Leitungswasser. Der Vorzucht folgte eine 4tägige Fermentation in einem Produktions‐Medium fol

ISSN:0044-2208    

DOI:10.1002/jobm.19780180409

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780180412

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780180414

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY