摘要:

AbstractThe SOS chromotest is a simple quantitative short‐term bacterial assay for the detection of genotoxic activity of pure compounds or complex samples. On the basis of consecutive experiments aimed at demonstrating the relationship between the inoculum size and the outcome of the test using 4‐nitroquinoline‐1‐oxide (4‐NQO) as model genotoxin. It is shown that within the suitable range of the cell number there is a negative correlation between the number of tester cells and test sensitivity. Moreover, it could be demonstrated that the peak of the dose response curve, i. e., the maximal induction factor, is systematically influenced by the actual value of the ratio of β‐galactosidase to alkaline phosphatase enzyme activities at a 4‐NQO concentration of zero. Last but not least, some simple statistical data describing the performance of the automated version of the SOS chromotest

ISSN:0233-111X    

DOI:10.1002/jobm.3620290702

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620290703

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe production of extracellular inhibitors byStreptomycessp. 1–72, specific either to trypsin (TI‐1), or to chymotrypsin (CI‐1), was investigated in relation to the cell growth and composition of the cultivation media. The biosynthesis of the inhibitors was found to be of a growth‐associated type which reached a maximum level at late exponential phase. All of the investigated carbon sources, including starch, disaccharides and monosaccharides, equally supported the production of both inhibitors, while the effect of the different nitrogen sources considerably varied, some of then being totally ineffective. The sources which mostly supported the biosynthesis of the inhibitors were tryptone (3%) for TI‐1, and peptone (3%) for CI‐1 r

ISSN:0233-111X    

DOI:10.1002/jobm.3620290704

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620290705

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe pattern of directed riboxin biosynthesis byBacillus subtiliswas studied in dependence on the cultivation conditions using the material‐energy balance method (MEB).By means of comparative evaluation of experimental and theoretical values of physiological indices received from the MEB equations, we determined the key fermentation periods where it was necessary to change both aeration and mixing regimes. During the period of controled biosynthesis characteristics of self‐regulation of the process have been observed, as expressed by periodical increases and decreases of glucose consumption rate and respiration intensity. The latter was inversely correlated to the velocity of riboxin synthesis and corresponded directly to changes of growth r

ISSN:0233-111X    

DOI:10.1002/jobm.3620290706

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620290708

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

摘要:

AbstractUsing four medium types (glucose‐, cellulose‐, 50% sucrose‐ and 10% NaCl‐CZAPEK's agar), it was possible to isolate 15 fungal genera, 78 species and 6 varieties. The collective fungal spectrum varied from one medium to another where the highest number of species (57 species/1000 seeds) was obtained on glucose‐ and the lowest (31 species/1000 seeds) on 10% NaCl‐CZAPEK's agar.Aspergillus, Penicilliumand sometimesRhizopusandChaetomiumwere the most common genera on the different medium types. The most common fungal species especially on glucose‐ and cellulose‐CZAPEK's agar were,Aspergillus niger, A. flavus, A. ochraceus, A. fumigatus. A. flavusvar.columnaris, Penicillium chrysogenum, Rhizopus stoloniferandChaetomium globosum.Members ofA. glaucusgroup were more frequently recovered on 10% NaCl‐ and 50% sucr

ISSN:0233-111X    

DOI:10.1002/jobm.3620290709

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620290711

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

摘要:

AbstractUsing the soil plate technique, thirty one species appertaining to twenty three genera were recovered from 160 samples of rabbit claws which were collected from a rabbit farm at Assiut. Of the true keratinophilic fungiChrysosporium tropicumwas the most prevalent where it colonized 56.25% of the samples.Microsporum gypseumwas rarely isolated in this study. Among the non‐keratinophilic fungiPenicillium funiculosum, P.jenseniandPaecilomyces lilacinuswere of low incidence (20%, 19.37% and 14.37% of the samples, respectively

ISSN:0233-111X    

DOI:10.1002/jobm.3620290712

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY

摘要:

AbstractPhaseolotoxin (N‐sulphodiaminophosphinyl‐ornithyl‐alanyl‐homoarginine) is a phytotoxic secondary metabolite produced byPseudomonas syringaepv.phaseolicola.The production of the phytotoxin is strongly regulated by temperature. The optimal temperature for phaseolotoxin production is 18 °C. Temperatures in the range between 18 °C and 30 °C inhibit the production of phaseolotoxin in an increasing manner. By temperature shift experiments and the inhibition of protein synthesis by chloramphenicol it was demonstrated, that the synthesis of enzymes related to toxin synthesis and not the regulation of the activity of the responsible enzyme system is affected by higher te

ISSN:0233-111X    

DOI:10.1002/jobm.3620290713

出版商:Wiley‐VCH    

年代:1989

数据来源: WILEY