摘要:

AbstractThe antibacterial activity of ten N‐alkylated derivatives of daunorubicin and adriamycin as well as of 5‐iminodaunorubicin has been tested by usingBacillus subtilis170,Escherichia coliB, andProteus mirabilisVI and their stable protoplast type L‐forms in an agar diffusion test. Eight of the substances showed similar activities againstB. subtilisand the L‐forms of all test organisms, but no activity against the bacterial forms ofE. coliandP. mirabilis.The cell wall of these gram‐negative bacteria is responsible for this resistance by not allowing the antibiotics to enter the cells. The piperidino compound N‐(CH2)5daunorubicin shows 2‐4 times higher activity againstR. subtilisand all L‐forms in comparison to daunorubicin and the other derivatives. Five of the substances were inactive against all test strains. Their inactivity seems to be associated with the larger substituents at the C‐3′ position. Relations between molecular structure and activity are discussed considering data about the interaction with DNA and the antitumor activity. Stable protoplast type L‐forms and their bacterial forms represent a suitable and effective test system to screen for more effective substances and to get more information about

ISSN:0044-2208    

DOI:10.1002/jobm.19820221002

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe physiological behaviour ofThermoactinomyces vulgaris— producing a thermostabile serine‐protease — was analyzed during fermentation. During 38 h the consumption of nutrients and oxygen as wll as the rates of macromolecular and protease synthesis were measured. The morphological and ultrastructural changes of the mycelia were also studied.The mycelia grew exponentially for about 5 hours. After a short lag and a second slower growth phase, growth continued about linearly until the end, as was indicated by a constant rate of incorporation of labelled thymidine. However, at the same time a changing portion of hyphae — up to 45% — underwent lysis. According to the changing ratio of growing and lysing material, regarding the physiological activity of the culture the fermentation process could be divided into 4 periods.The formation of the protease started at the transition to the slow growth phase and continued linearly. The ability to produce the protease was attributed to a mycelium being formed after the shift down caused by limitation of supply of utilizable nitrogen compounds. The end of protease production 10 h later was correlated to a drastic decrease of the respiratory activity of the mycelia, probably caused by exhaustion of easily utilizable carb

ISSN:0044-2208    

DOI:10.1002/jobm.19820221003

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA strain ofCandida albicanswas found to have an associative temperature profile with respect to growth, thermal death and yield on glucose. The ARRHENIUS plot of sustained exponential growth displayed two branches in the supraoptimal temperature range with the optimum temperature for growth around 33°C, the final maximum temperature for growth around 38°C and the initial maximum temperature for growth around 42°C. The yield on glucose was temperature dependent in the supraoptimal range and declined linearly to zero between the optimum and the initial maximum temperature for grow

ISSN:0044-2208    

DOI:10.1002/jobm.19820221004

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA temperature sensitive mutant ofBacillus subtilisSB 19, straints33‐6 was characterized. This strain grows at 46°C (restrictive temperature) with reduced intensity without septation processes. Under restrictive conditions DNA‐ and RNA‐synthesis are remarkably reduced. DNA, however, is synthesized continuously under restrictive conditions causing the formation of multinuclear filaments. Septation, induced at permissive temperature, is not prevented under restrictive conditions. That means that under restrictive conditions initiation of septation is blocked whereas formation of septa can be observed. Shift‐up experiments have shown that the initiation of septation processes occurs at an early stage of ce

ISSN:0044-2208    

DOI:10.1002/jobm.19820221005

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractInduction of synchrony by various perturbations in continuous yeast cultivation on hydrocarbons of crude oil is described. Short‐time temperature and pH‐value shocks cause oscillations of budding cell percentage in the order of the cell cycle duration. An abrupt change of the phosphate ion concentration of the nutritional medium may also induce a synchronization of microbial growth. However, the frequency corresponds with the eigenfrequency of the fermentation process. The experimental values were investigated statistically using autocorrelation and spectral analy

ISSN:0044-2208    

DOI:10.1002/jobm.19820221006

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe application of immobilized microbial cells has been receiving increasing interest, in particular because of their potential for use in industrial fermentation processes and in analytical procedures. Since the first application of an immobilized microbial biocatalyst for steroid transformation in 1970 by MOSBACH and LARSSON many results have been published concerning the use of such type of biocatalyst in steroid biochemistry and steroid microbiology, respectively. The review deals with the present scientific state of the steroid transformations performed with immobilized biocatalysts, their applications and development trends. In particularly the following aspects are discussed: 1(2)‐dehydrogenation or hydrogenation, hydroxylation reactions, redox processes in 3,17‐ and 20‐oxogroups, side chain splitting of sterols, 5α‐reduction, modification of cholic acid derivatives and the use of immobilized plant cells. The possibility for application of microbial membrane electrodes in steroid analysis has been shown. Up to now, many results of fundamental research are known. There are possibilities for producing expensive steroid derivatives in laboratory apparatures using immobilized biocatalysts. Some of the processes, described here, are of practical interest, and some of them are said to be used industrially, resp

ISSN:0044-2208    

DOI:10.1002/jobm.19820221007

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19820221009

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19820221011

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19820221001

出版商:Akademie‐Verlag    

年代:1982

数据来源: WILEY