摘要:

AbstractIn a continuing search for new antibiotics, the speciesActinomadura rubra(Sveshnikovaet al.)J. MEYERetM. SVESHNIKOVA1974 (strain IMET 13001) was found to produce a red pigment with indicator properties, designated maduramycin. The pigment (C28H22O10; m.w. 518 m/e−; m.p. 305‐310 °C (dec.); uvmax225.307 nm) possesses a strong antimicrobial activity against grampositive bacteria, including strains which produce inactivating enzymes for some commercial antibiotics. Maduramycin forms a complex with serum albumin, but no complex formation with DNA was observed using absorption spectroscopic and polarographic methods. Maduramycin additionally inhibits the action of some enzymes. The LD50of maduramycin in mice was>250 mg/kg on intraperitoneal administration. Fermentation, isolation, and some of the chemical and biological properties of this new antibiotic are descr

ISSN:0044-2208    

DOI:10.1002/jobm.19780180602

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCystobacterspecies strain CK 1 does not grow with more than 0.2 μg/ml acriflavine. Spontaneous two‐step mutants growing with 2 μg acriflavine per ml have been selected. One mutant (strain CK 3) was used to investigate the effect of repair inhibitors. Both strains exhibit pronounced shoulders in their UV dose curves of inactivation. Acriflavine (AF), coumarin (CU), and caffeine (CA) when incorporated in the post‐irradiation plating medium decreased survival of irradiated cells. Post‐treatment with 2 μg acriflavine/ml abolished the shoulder of the curve. Caffeine (1600 μg/ml) and coumarin (350 μg/ml) reduced it only to about 40%. It is concluded that probably two repair mechanisms are present.Pre‐treatment of the cells with 2 μg acriflavine/ml for two hours before UV‐irradiation resulted in a constant dose enhancement factor of 1.9. The protective effect is increased with the time of treatment with acriflavine. This may indicate that pyrimidine dimers are responsible for

ISSN:0044-2208    

DOI:10.1002/jobm.19780180603

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe stable L‐form ofErysipelothrix rhusiopathiaeis a typical protoplast type L‐form. Cells are surrounded by a trilamellar cytoplasmic membrane only. They grow in form of aggregations in liquid media and their diameters vary between 0.1 and 2 μm. Always a large portion of cells undergoes lysis. It seems to be characteristic for L‐form cultures ofE. rhusiopathiaethat always many artifact structures are formed. The artifacts are spherical particles with diameters of 0.1 μm to more than 3 μm. They can be differentiated from L‐form cells only by electron microscopy. The artifacts consist of electron dense amorphous material and their surface is irregular without a clear boundary line. Obviously, these artifacts are produced from protein components of the medium and from cytoplasmatic components of the lysing L

ISSN:0044-2208    

DOI:10.1002/jobm.19780180604

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractWhenE. coliML 30 is grown in batch culture on a mineral salt medium containing a mixed carbon source of glucose and pyruvate, there is no sequential utilization of the carbon sources. The consumption of glucose and pyruvate takes place simultaneously with reciprocal influence (inhibition) on rates of substrate uptake. The specific growth rate is greater than μpmax for pyruvate but smaller than μsmax for glucose. In the paper three cases of kinetics of growth and of substrate consumption at several combinations of initial substrate concentrations are considered. A mathematical model is proposed and investigated. The model allows to describe the growth on glucose or on pyruvate not only as singular carbon sources, but also as a mixed carbon source with reciprocal inhibition on rates of substrate uptake. By data fitting parameters of growth and substrate consumption were foun

ISSN:0044-2208    

DOI:10.1002/jobm.19780180605

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractWachstum mit Oxalat und Citrat konnte bei 2 der vonSCHULZEu.SCHWEINSFURTH(1971) isolierten Stämme durch Eisen gefördert werden, wobei ein Fe(II)‐Zusatz einen stärkeren Effekt zeigte als ein Zusatz von Fe(III). Bei Stamm 31 konnte der positive Effekt durch Eisen auf ein physiologisch günstiges tieferes pH zurückgeführt werden, das sich bei der Bildung von Fe(III)‐hydroxid einstellt. St. 68 dagegen zeigte auch bei konstantem pH einen positiven Wachstumseffekt von Eisen. Mikroaerophile Bedingungen im Kulturmedium mit Eisen hemmten das

ISSN:0044-2208    

DOI:10.1002/jobm.19780180606

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractEs wird ein Literaturüberblick zur Gewinnung und Charakteristik von Proteasen aus thermophilen Mikroorganismen gegeben. Nach einem allgemeinen Überblick zur Problematik der Thermophilie wird auf die von Schimmelpilzen und Bakterien produzierten proteolytischen Enzyme eingegangen. Besonders hervorgehoben werden die Protease ausStreptomyces rectus var. proteolyticus, die „Aminopeptidase I”︁ ausBacillus stearothermophilussowie das Thermolysin ausB. thermoproteo

ISSN:0044-2208    

DOI:10.1002/jobm.19780180607

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractChlorella fuscawas grown asynchronously for 2 weeks in media with different Zn concentrations up to 10−3m. Growth was optimal at 10−5m Zn. The Zn contents of the algae were followed by activation analysis. They increased with increasing Zn concentration in the media, and, except with the lowest Zn concentrations, with time. Further, the uptake of labelled Zn (65Zn) from 5 · 10−6m solution by cells of known Zn content was measured at 30 °C during one day in minimum and optimum conditions (dark/nitrogen or light/air, respectively). The rate of uptake showed a maximum with algae grown in a medium with 10−5m Zn. However, algae exposed to a lethal Zn concentration (10−3m) also absorbed much Zn; this anomalous uptake is ascribed to a breakdown of the cell membrane as a permeabil

ISSN:0044-2208    

DOI:10.1002/jobm.19780180608

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780180609

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780180610

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780180611

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY