摘要:

AbstractTo determine to what extent methanol in addition to the commonly used glucose is an attractive alternative feedstock for glutamic acid production, a comparative theoretical consideration of possible yields is given. Methanol can be assimilated by bacteria via three different metabolic pathways. With regard to the corresponding energy balance equations the overproduction process is either energy‐deficient, energy‐neutral or energy‐excess. The theoretical maximum yields of glutamic acid synthesis with methanol as a substrate are not substantially lower than based on glucose. In one case the value is even higher. From the aspect of possible yields methanol would not be less convenient than glucose and the serine pathway seems to be the most suitable one for the synthesis of glutamic

ISSN:0233-111X    

DOI:10.1002/jobm.3620340402

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe effects of growth rate and nutrient limitation on monobactam production, peptidoglycan content and mean cell length inPseudomonas aeruginosawas studied using continuous culture techniques. All three parameters increased progressively with growth rate, a greater response being shown under carbon limitation compared to that occurring under nitrogen limiting conditions. Interestingly, monobactum production mirrored peptidoglycan synthesis. In addition, the monobactam exhibited a broad range of antibacterial activity and bound preferentially to PBP 1A in the producing organism. Moreover, addition of the monobactam to a growing culture inhibited cell wall synthesis. These results are discussed in relation to the control and regulation of peptidoglycan synthesis.

ISSN:0233-111X    

DOI:10.1002/jobm.3620340403

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractAn interrelationship between primary and secondary metabolites of a toxigenic mould(Aspergillus parasiticusvar.globosusIMI 120920) was obtained in liquid broth containing various concentrations of dithaneZ‐78 and propoxur. The results show that a stimulatory response was recorded in gibberellin, protein, sterol and aflatoxin yield in cultures treated with 15, 30, 50 and 100 ppm a.i. of dithane Z‐78. On the other hand, propoxur reduced the yield of gibberellin, amino acids, protein, sterol and aflatoxin. In comparison to its effect on the mycelial growth, gibberellin and aflatoxin activity is inhibited more severly than dry weight increase, thus leading to the assumption that there is a specific effect of the inhibitor on both gibberellin and aflatoxin synthe

ISSN:0233-111X    

DOI:10.1002/jobm.3620340404

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractEncapsulation of seeds with alginate entrapped rhizobia (AER) bead has been developed as a new seed‐applied inoculum technique for utilizing legume‐Rhizobiumsymbiosis for the management and protection of natural ecosystems. Alginate beads trapped water and immobilized rhizobia which ensured germination of seeds and nodulation of seedlings. Incorporation of a synthetic polymer, Jalshakti, in alginate beads did not enhance symbiotic nitrogen fixation but sufficient number of rhizobia remain viable in them even after 30 weeks of storage reflecting suitability of these materials as carriers for rhizobia. Plant cultures raised from these beads were similar to or even better than the inoculated controls in symbiotic parameters indicating the effectiveness of seed‐applied inoculum technique. Pelleting of seeds with these polymers after coating with gum arabic lead to substantial reduction in symbiotic association and viability of rhizobia. Experiments involving two legume‐Rhizobiumassociations indicated that the encapsulation of seed with AER bead is a cheap, inexpensive and effective inoculation technique which may be used in aerial

ISSN:0233-111X    

DOI:10.1002/jobm.3620340405

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620340406

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractAeromonas caviae, often reported to be associated with diarrhoeal patients, elaborates several virulence factors as well as catabolic enzymes such as xylanase and β‐galactosidase. Studies on the kinetics of growth ofA. caviaeand synthesis of β‐galactosidase suggested that the activity was cell associated and reached a peak during the late logarithmic phase of growth. The optimum pH for β‐galactosidase activity was 7.0 and required Ca2+and glutathione for enhancement of its activity; IPTG also slightly improved the activity. Aerobic cultivation ofA. caviaein LB containing glucose, fructose, maltose and sucrose completely inhibited the activity possibly due to acetic acid production. Addition of 100 mM cAMP to the media containing glucose (0.25%, w/v) restored the relative activity by 8.8%; however, the final pH of the media remained acidic. Aerobic growth ofA. caviaewith other carbon sources did not affect β‐galactosidase activity, probably as there was no acid production and thereby the final pH of the media unaltered. Arabinose, xylose and galactose induced theA. caviaeβ‐galactosidase activity by several folds and lactose moderately enhance

ISSN:0233-111X    

DOI:10.1002/jobm.3620340407

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractThe histidine utilization geneshutHandhutUofPseudomonas putidaATCC 12633 have been mapped by interrupted mating and transduction to a location at approximately 43 minutes on the chromosome, closely linked toser‐800andmet‐400markers previously shown to be at 46 and 42 minutes, respectively. Since restriction enzyme mapping and cloning results have established that all genes associated with thehutpathway are contiguous, earlier maps of this strain which place these genes near 10 minutes on the chromosome in a superoperonic catabolic cluster are in er

ISSN:0233-111X    

DOI:10.1002/jobm.3620340408

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620340409

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractEffect of cyanate on nitrate reduction byRhizobium melilotiSU47 was studied. In the presence of cyanate assimilatory nitrate reduction activity appeared in the culture after a long lag and a conspicuously low level of nitrite was accumulated. Dissimilatory nitrate reduction activity was low in the intact cells precultured in KCNO of KNO3as compared to that in the control. Dissimilatory nitrate reductase activity in the extracts of cells precultured in KCNO was also compared to be low. In the extracts, dissimilatory nitrate reductase activity assayed with increasing concentrations of KCNO confirmed that KCNO acts as an inhibitor of the enzyme.

ISSN:0233-111X    

DOI:10.1002/jobm.3620340410

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY

摘要:

AbstractA L‐lysine α‐oxidase (LOD) has been purified to homogeneity in a two‐step procedure with 300‐fold enrichment and 60% recovery from the culture extract ofTrichoderma viridei4. The enzyme catalyzes the reaction between L‐lysine and molecular oxygen forming 2‐oxo‐6‐aminocaproate, ammonia and hydrogen peroxide. Numerous substrates have been tested. TheKmvalue for L‐lysine was found to be 0.026 mM. Its apparent molecular mass is 110000 Da when determined by gel filtration on Sephadex G‐200, the estimated molecular weight of the subunits being 55000 Da in the SDS‐PAGE. The enzyme is a glycoprotein and shows absorption maxima at 276, 386 and 463 nm. It was found to contain 1 mol of FAD per subunit. The coenzyme is bound non‐covalently. Its isoelectric point is at pH 4.3. The enzyme is stable at extreme pH values, at relatively high temperatures and in diluted hydrogen peroxide.The enzyme described here differs from two other known L‐lysine oxidases previously characterized with regard to its amino acid composition and

ISSN:0233-111X    

DOI:10.1002/jobm.3620340411

出版商:Wiley‐VCH    

年代:1994

数据来源: WILEY