摘要:

AbstractThe present study reports the sensitivity of ten different wood‐rotting fungi towards eight samples of tea and two samples of coffee. The tea samples included five CTC black teas, one orthodox black tea and two green teas. The different fungi tested were sensitive to different tea and coffee samples to variable levels. Green tea caused the maximum growth inhibition and it was 100% in case ofPhanerochaete chrysosporiumandSporotrichum pulverulentum. Of the black tea samples, orthodox black tea was more effective inhibitor for all the fungi tested.Phlebia radiatawas the most sensitive fungus to all the black tea samples except Lipton Cheers. The growth ofDaldinia concentricawas least affected by all the black tea samples. The two coffee samples showed better inhibition than CTC black tea samples. The inhibitory effect of tea and coffee extracts was greatly reduced on their filtration. All the tea and coffee samples tested showed more than 50% reduction in their inhibitory activity. The inhibitory effect was completely lost in spent black tea leaves. The antifungal effect of pure caffeine was tested at different concentrations. Majority of the fungi were totally inhibited at a concentration of 0.3% whereas,D. concentrica, P. radiataandP. palustrisshowed complete inhibition at a concentration of 0.5 percen

ISSN:0233-111X    

DOI:10.1002/jobm.3620370302

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620370303

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe effect of exposingAcinetobacter calcoaceticus69‐V to DNP1‐stress and heat shock was examined by two‐dimensional gel electrophoresis of proteins, which were detected either by autoradiography or by silver staining. Both DNP stress and heat shock led to altered patterns of protein synthesis or concentration. About 10% of the proteins which were synthesized newly or at an increased rate and about 25% of those which were found newly or with an increased concentration after DNP treatment were identified after heat shock

ISSN:0233-111X    

DOI:10.1002/jobm.3620370304

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractAryl‐β‐D‐glycosides have been described as intermediates in lignin biodegradation. The catabolism of this kind of compounds has been poorly studied. In this work, the isolation and initial characterization of a bacterial consortium degrading vanillyl‐β‐D‐glucopyranoside is reported. The consortium is able to grow on and completely degrade the dimer vanillyl‐β‐D‐glucopyranoside. The consortium is composed of three microorganisms: strain 2.1 is closely related toChryseomonas luteola; strain 2.2, identified asMoraxella phenylpyruvicaand strain 2.3, preliminary identified asPseudomonasspp. Complete degradation of the glycoside required strains 2.1 and 2.2, although only strain 2.1 was able to cleave the aryl‐glycoside linkage. Oxidation of vanillyl alcohol, one product of the aryl‐glycoside cleaving reaction, to the respective acid was carried out by strain 2.2. Vanillic acid was used as growth substrate by strains 2.2 and 2.3. Strain 2.1 can grow on other aryl‐β‐glycosides, accumulating the aryl moiety in the culture. β‐Glucosidase present in strain 2.1 is probably the key enzyme in the catabolism of ar

ISSN:0233-111X    

DOI:10.1002/jobm.3620370305

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractEnzymes of the glutathione‐dependent detoxification pathway (glutathione S‐transferase and γ‐glutamyl‐transpeptidase)1) were induced, and the glutathione pool was completely depleted by phenoxyacetic acid inPenicillium chrysogenummycelia incubated for 15 h in a culture medium containing lactose as a carbon source and sodium glutamate as a nitrogen source. A significant increase in both the oxidised glutathione concentrations and the glutathione reductase activities were also observed. 1‐Chloro‐2,4‐dinitrobenzene ‐ a potent substrate and inducer of glutathione S‐transferase ‐ initiated very similar physiological changes but no β‐lactam production could be detected in this case. When (NH4)2HPO4was used as a nitrogen source the penicillin biosynthesis was repressed and the induction of γ‐glutamyltranspeptidase by phenoxyacetic acid

ISSN:0233-111X    

DOI:10.1002/jobm.3620370306

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractFour bacteriocin producing lactic acid bacteria isolated from vegetables were identified asLactococcus lactisstrains on the basis of physiological and biochemical characteristics, carbohydrate fermentation patterns and analysis of total soluble protein pattern by SDS PAGE. The bacteriocins had a wide spectrum of activity as antagonism was detected not only towards a variety of lactic acid bacteria, but also toStaphylococcus aureusandListeria monocytogenes. These bacteriocins were resistant to heating at 121 °C for 15 minutes and showed highest activity at low pH (<5.0). They were inactivated by the proteolytic enzymes α‐chymotrypsin and proteinase K, but not by lipase, α‐amylase, catalase or lysozyme. These bacteriocinogenicLactococcusstrains were all immune to the bacteriocins produced as well as to commerical nisin. Bacteriocin producer culture supernatants showed a high degree (70 or 100%) of cross‐reactivity in the nisin ELISA, suggesting similarity of the produced bacteriocins to nisin. The potential application of bacteriocin producing lactococci of vegetable origin for safety assurance of vegetable foods and controlling vegetable fermentations is d

ISSN:0233-111X    

DOI:10.1002/jobm.3620370307

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe effects of certain nutrients on dextransucrase (sucrose: 1,6‐α‐D‐glucan 6‐α‐D‐glucosyltransferase EC 2.4.1.5) production fromLeuconostoc mesenteroidesNRRL B‐512F were studied. An increase in concentration of sucrose to 4% in the enzyme production medium resulted in the increase of activity of dextransucrase. Higher enzyme yields were obtained at low yeast extract and high phosphate concentrations. The presence of peptone and beef extract in the medium in addition to 2% yeast extract resulted in an enhanced production of dextranscucrase. The enzyme activity increased by 30% by both peptone and beef extract. Addition of Tween 80 to the medium enhanced the production of enzyme and the activity was increased by 25%. Magnesium ions stimulated the acitivity marginally. Sodium fluoride enhanced the activity of dextra

ISSN:0233-111X    

DOI:10.1002/jobm.3620370308

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe capability of the intestinal flora from the gut of xylophagous termites of degrading lignin model compounds was investigated. Different dimeric lignin model compounds‐degrading bacteria were obtained from the hindgut flora ofMastotermes darwiniensisFROGGATT,Reticulitermes santonensisFEYTAUD,Nasutitermes nigricepsHALDEMANandZootermopsis angusticollisHAGEN. In the presence of oxygen dimeric model compounds were degraded by all isolates. This indicates that the hindgut flora of termites is basically able to produce substrate for their host from aromatic extractives of woo

ISSN:0233-111X    

DOI:10.1002/jobm.3620370309

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620370310

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe effect of the carbon source succinate on pyrimidine synthesis in the pathogenBurkholderia cepaciaATCC 25416 was investigated. The fivede novopathway enzyme activities of pyrimidine biosynthesis inB. cepaciawere shown to be affected when ATCC 25416 cells were grown in the presence of uracil. Pyrimidine limitation of a uracil auxotrophicB. cepaciastrain lacking orotidine 5′‐monophosphate decarboxylase activity increased aspartate transcarbamoylase, dihydroorotase, dihydroorotate dehydrogenase and orotate phosphoribosyltransferase activities by at least 1.5‐fold which indicated that these pathway enzymes may be regulated by a uracil‐related compound. The levels of thede novopyrimidine biosynthetic enzyme activities inB. cepaciaATCC 25416 cells appeared to be influenced to a greater degree in cells grown on succinate than on glucose as a carbon

ISSN:0233-111X    

DOI:10.1002/jobm.3620370311

出版商:Wiley‐VCH    

年代:1997

数据来源: WILEY