摘要:

AbstractMycobacteriumsp. NRRLB3683 which is capable to convert β‐sitosterol to 1,4‐androstadiene‐3, 17‐dione (ADD) was treated with methyl methane sulfonate and two strains with altered sensitivity to various antibiotics were obtained. One of the strain was steroid 1(2)‐dehydrogenase negative and the other positive. Efficiency of utilization of sterols followed the order β‐sitosterol>cholesterol>soluble cholesterol. The steroid 1(2)‐dehydrogenase negative strain was capable of producing 17KS (AD) from β‐sitosterol and converting AD to testosterone and ADD to AD suggesting the negative role of 1(2)‐dehydrogenase in sterol side chain cleavage and decrease in hydrogenase activity by mutation. But this enzyme can perform the reverse reaction und

ISSN:0233-111X    

DOI:10.1002/jobm.3620360602

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractDaily mould counts were made using both exposed slides and Petri dishes, from January 1, 1994 to December 31, 1994 in Europe Quarter of Istanbul, Turkey. The most important moulds were:Cladosporium, Alternaria, Penicillium, Aspergillusand yeast. The peak mould season was early January to early February. Some moulds were present all year.

ISSN:0233-111X    

DOI:10.1002/jobm.3620360603

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractIn this study the variability of fungal flora in the atmosphere during morning and evening hours in different districts of Istanbul is investigated. The results are that in all districts in the evening the density is high of moulds,PenicilliumandAspergilluswhile in the morning hours,CladosporiumandAlternariadensities are high. The density ofLeptosphaeriain the atmosphere decreases at night or equalizes compared to the morning rate. The rate ofUstilagodiffers in the morning and evening hours in different districts. There is no differentiation in the build‐up rate of other fungus gener

ISSN:0233-111X    

DOI:10.1002/jobm.3620360604

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractThe ribosomal RNA gene restriction patterns (ribotyping) was investigated with respect to the characterization ofRhodococcusspecies andR. rhodochrousstrains. Chromosomal DNA was prepared, digested with BamH I, blotted, and hybridized with acetylaminofluorene‐labelled 16 + 23S rRNA fromE. coli. The type strains of sevenRhodococcusspecies studied gave different hybridization patterns in each case. All strains tested were clearly distinguishable by ribotyping. Patterns contained two to eight bands between 1.4 kb and 11.8 kb and demonstrated the high genetic divergence of genusRhodococcus. Investigation of nineR. rhodochrousstrains resulted in patterns with seven or eight bands. One fragment. 4.4 kb in size, was common to allR. rhodochrousstrains and appears to be characteristic ofR. rhodochrous. Ribotyping was evaluated as a tool for distinguishing betweenRhodococcusspecie

ISSN:0233-111X    

DOI:10.1002/jobm.3620360605

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractVancomycin, an inhibitor of peptidoglycan synthesis, depressed the growth ofMycobacteriumsp. NRRL B 3805 and MB 3683, but not the β‐sitosterol side chain degradation and androstane derivatives accumulation. As a result, the specific activity (products formed/cell weight unit × h) increased threefold in the peptidoglycan‐deficient cells, indicating faster crossing of the sterol through the cell water barrier.Cell wall preparations: crude cell wall (CCW), purified cell wall (PCW), and peptidoglycan — enriched PCW — residue (PEPCW) were obtained and analysed in order to find a relationship between the vancomycin — induced chemical changes and the permeation rate of the sterol.The amounts of CCW, PCW and PEPCW, produced from 8 g lyophilised control cells were 445, 170 and 28 mg respectively. The respective figures were 176, 61, and 4.8 mg for vancomycin — treated cells. In addition to the lower content of the rigid layer, a distinct shift in the molar ratios of the peptidoglycan constituents: alanine, glutamic, diaminopimelic and muramic acids, and glucosamine was observed under the action of the murein inhibitor. The most significant change was that of muramic acid: diaminopimelic acid molar ratio, the compounds which are markers of glycan strands and tetrapeptides, respectively. In control cells it was approximately 1:1, and increased to 1.34–1.43: 1 in the compared preparation, which indicated a marked decrease in the tetrapeptide moieties crosslinking the main glycan strands. Together with the general lower content of murein, this modification may be responsible for the enhanced sterol permeation throug

ISSN:0233-111X    

DOI:10.1002/jobm.3620360606

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractCassava wastes — the peel and the root fibre were taken through various pretreatment procedures before being subjected to solid state fermentation withTrichoderma harzianum. Most of the pretreatment processes increased the cellulose and hemicellulose content of the cassava peel and fibre by as high as 155% while sulfuric acid treatment resulted in 25.3% loss in the peel hemicellulose. The best pretreatment found to be 1% NaOH at 120 °C gave the highest production of the Cx, the C1and xylanase enzymes with the cassava root fibre. Xylanase and cellulase production with the exception of the Cxwas found to be affected by age while an improved cassava variety TMS(2) 1425 peel and fibre rated highest in terms of production of the enzymes. Percentage hydrolysis within range of 56.52–67.64% were recorded for the enzymes on sorghum gr

ISSN:0233-111X    

DOI:10.1002/jobm.3620360607

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractNitrate uptake, nitrite efflux and their regulation have been studied in the cyanobacteriumNostocMAC. Nitrate uptake as well as nitrite‐assimilation‐dependent nitrite efflux systems consisted of two distinct phases comprising an initial rapid phase followed by a slower one. Whereas, 3‐(3,4‐dichlorophenyl)‐1‐1 dimethyl urea (DCMU), an inhibitor of photosystem II inhibited both nitrate uptake and nitrite efflux significantly, exogenous supply of ATP, however, stimulated both the processes, suggesting that PS II‐mediated energy generation plays vital role in regulating both nitrate uptake as well as nitrite efflux. The inhibition of both the processes byp‐chloromercuribenzoate (pCMB)1, N,N dicyclohexylcarbodiimide (DCCD) and carbonyl cyanide‐m‐chlorophenyl hydrazone (CCCP) indicated the involvement of ‐SH groups and ATP hydrolysis in the regulation of both the processes. Tungstate‐treated cells having nonfunctional nitrate reductase although had a significant level of nitrate uptake, yet nitrite efflux by these cells was found to be negligible. These results suggest that (i) nitrate uptake and nitrite efflux processes inNostocMAC are energy‐dependent; (ii) assimilation of nitrate via nitrate reductase is necessarily required for nitrite efflux to occur; (iii) nitrate uptake and nitrite efflux processes are regulated at different levels by different metabolic inhibitors; and (iv) cations of larger ionic radius facilitate the nitrate uptake and

ISSN:0233-111X    

DOI:10.1002/jobm.3620360608

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractTemperate phage χ originated from the defectively lysogenicSerratia marcescensstrain K, from where it was liberated after uv irradiation with low efficiency. The phage is usually indicated on strain HY that can be easily lysogenized by it and rather efficiently uv‐induced. Comparing theEcoRI restriction profiles of the χ prophage in HY revealed a DNA rearrangement, by which the precursor structure in K is converted into the non‐defective form. Apparently the fragment containing thepacsequence is concerned since a phage DNA probe prepared from the assumed initiation fragments of the first particles of the packaging series gave two signals instead of one with genomic K DNA. Since several independent new χ isolates showed the sameEcoRI restriction pattern as the original phage of ELLMAUER and KAPLAN (1959), the generation of χ is a reproducibl

ISSN:0233-111X    

DOI:10.1002/jobm.3620360609

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractStudies on the effect of various Cd2+concentrations on substrate oxidation by whole cells of cadmium‐sensitiveStaphylococcus aureus17810S showed that oxidation of glutamate or pyruvate was highly sensitive to low Cd2+concentrations (5 μM), whereas L‐lactate oxidation was insensitive even to high Cd2+concentrations (100 μM). Location of the cadmium‐sensitive targets in the enzyme systems involved in oxidation of these substrates was studied in subcellular fractions prepared from cells pretreated with 5 or 100 μM Cd2+. Activities of the cytoplasmic 2‐oxoglutarate dehydrogenase complex (ODHC)1) and pyruvate dehydrogenase complex (PDHC) were strongly inhibited with 5 μM Cd2+, while with 100 μM Cd2+the inhibition was almost complete. In contrast, activities of the cytoplasmic NAD‐dependent glutamate dehydrogenase (NAD‐GDH), the membrane‐bound NADH dehydrogenase (NDH) and HQNO‐sensitive NADH oxidase were not sensitive to 100 μM Cd2+. These data indicate that the accessible, cadmium‐sensitive targets are located only in the cytoplasmic ODHC and PDHC. It is postulated that two vicinal dithiols present in ODHC and PDHC may be regarded as the primary cadmium‐sensitive targets in the systems oxidizing glutamate or pyruvate. Since activities of the membrane‐bound NAD‐independent L‐lactate dehydrogenase (iLDH) and HQNO‐sensitive L‐lactate oxidase were not affected by 100 μM Cd2+, this indicates that the L‐lactate oxidizing system lacks the accessible, cadmium‐sensitive targets. The mechanism of Cd2+toxicity to energy conservation with glutamate, pyruv

ISSN:0233-111X    

DOI:10.1002/jobm.3620360610

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY

摘要:

AbstractThe strains 48b/90 and 22d/93 are naturally occurring ephiphytes which were isolated from soybean leaves. On the basis of pheno‐ and genotypic characteristics 48b/90 was identified asErwinia herbicolaand 22d/93 asPseudomonas syringae. These two isolates produced biological active substances against different indicator organisms. TheE. herbicolastrain showed clear antagonistic properties againstEscherichia coliandPseudomonas syringaepv.glycinea, but not againstGeotrichum candidum. 22d/93 was active againstP. glycineaandG. candidum, but not againstE. coli. Strain 48b/90 produced at least two different inhibitors: an antibiotic substance and an inhibitor of the alginate synthesis. Strain 22d/93 produced at least three different compounds inhibitory toP. glycineaand one toG. candidum. Their activities against the bacterial blight pathogen,P. glycinea, can be observedin planta, too. Under the influences of the antagonists the pathogen multiplied at lower rates and to lower stationary phase population levels. The development of bacterial blight symptoms was suppresse

ISSN:0233-111X    

DOI:10.1002/jobm.3620360611

出版商:Wiley‐VCH    

年代:1996

数据来源: WILEY