摘要:

T.K. BHAT, H.P.S. MAKKAR AND B. SINGH. 1996. Faecal samples of 52 hill cattle fed largely on oak leaves were screened for tannin‐protein complex‐degrading micro‐organisms under different culture conditions using tannin‐treated brain heart infusion agar medium. None of the animals were found to harbour tannin‐protein complex‐degrading enterobacteria. However, a fungus identified asAspergillus nigervan Tieghem having tannin‐protein complex‐degrading activity, was consistently isolated from the faeces of such animals. Optimum growth and sporulation was noticed under aerobic conditions at 30°C on Czapek Y

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01155.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

P. LAURENT, H. RIPOUTEAU, V. COSMAO DUMANOIR, E. FRACHON AND M.‐M. LECADET. 1996. Serotyping ofBacillus thuringiensisis possible using 96‐well microplates instead of tubes. The advantages are a reduction on the incubation time from 120 to 75 min and the amounts of antisera and bacterial suspensions needed 10

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01156.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

R.N. WATERHOUSE, H. BUHARIWALLA, D. BOURN, E.J. RATTRAY AND L.A. GLOVER. 1996. CCD image‐enhancement was used to detectlux‐markedPseudomonas syringaepv.phaseolicolaL‐form bacteria in association with Chinese cabbage. Bioluminescence from colonizing bacteria was maximal 8 d after association. Bioluminescing L‐forms were reisolated from 22 d post‐association tissue. L‐forms but not parental, cell‐walled forms, were effective at inducing protection against a heterologous pathogen (Xanthomona

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01157.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

R.H. DAVIES AND C. WRAY. 1996. A one‐step test unit was developed which allowed migration of salmonellas to selective medium and indicated the presence of salmonella by motility inhibition using polyvalent flagella antiserum. Evaluation of the method using 1038 naturally contaminated samples led to identification of more contaminated samples than a standard method within 24 h as opposed to 96

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01158.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

T. FUJISAWA AND M. MORI. 1996. The β‐glucuronidase activity of intact cells ofEscherichia coliandClostridium perfringenswas increased in the presence of bile salts. In contrast, bile salts had inhibitory effects on the activity of β‐glucuronidase extracted from the lysed cells. These results suggest that the permeability of the bacterial cells is increased by the presence of bile salts, and that bile salts may significantly enhance bacterial β‐glucuronidase activity in the intestin

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01159.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

F. FAVA, F. BALDONI AND L. MARCHETTI. 1996. Crude extracts ofPseudomonassp. CPE2 strain, which is capable of growing on 2‐chlorobenzoic acid (2–CBA) and 2,5–dichlorobenzoic acid (2,5–dCBA) in the absence of other carbon sources, were found to be capable of bioconverting 2–CBA and 2,5–dCBA to catechol and 4–chlorocatechol, respectively, by a reaction requiring molecular oxygen and exogenous NADH. Extracts obtained from 2–CBA‐grown cells in the presence of 2–CBA and from 2,5–dCBA‐grown cells in the presence of 2,5–dCBA were found to have activities similarly influenced by the assay parameters pH, temperature, and by concentration of oxygen, protein, Fe2+, FAD and NADH in the assay medium. In addition, the activity of the two crude extracts in the presence of 2–CBA or 2,5–dCBA was described by very similar Michaelis‐Menten kinetic parameters. These observations led to the speculation that a unique broad‐spectrum chlorobenzoate 1,2–dioxygenase catalyses the 2–CBA and 2,5–dCBA metabolism both

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01160.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

K.Y. KIM, J.F. FRANK AND S.E. CRAVEN. 1996. The objective of this study was to locate the position of attached or entrappedSalmonellacells in poultry skin. Confocal scanning laser microscopy (CSLM) was used to obtain optical sections of intact poultry skin without artefacts associated with dehydration and other sample preparation techniques. A technique was developed to prevent compression of the poultry skin during CSLM operation. Images of bacteria and poultry skin were obtained after staining with Pyronin‐Y. Data indicated thatSalmonellacells were mostly located in the cervices and feather follicles.Salmonellain feather follicle floated freely in surrounding liquid even after the skin was thoroughly rinse

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01161.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

J. ROSS, P.I. BOON, R. SHARMA AND R. BECKETT. 1996. As current techniques for the quantification of bacteria are laborious and often imprecise, instrumental approaches such as sedimentation field‐flow fractionation (SdFFF) are attractive. In this technique, fluorogenic dyes specific for nucleic acids are used to identify bacterial cells. Bacterial biomass can be quantified directly with SdFFF if the specific fluorescence of bacterial cells is constant. The effect of different growth conditions on the specific fluorescence of one strain each ofEscherichia coli, Pseudomonas aeruginosa, Proteus mirabilisandStaphylococcus epidermidisstained with 4',6‐diamidino‐2‐phenylindole was examined. Specific fluorescence varied over a 500‐fold range, from 0.22 to 103 arbitrary fluorescence units per cell. Specific fluorescence was highest when cells were in log phase, and lowest when cells were in stationary phase. Specific fluorescence decreased when cells harvested in log phase were starved for 7 d in a carbon‐free minimal medium, and increased rapidly (within 2 h) after cells were relieved from carbon limitation. Such variations in specific fluorescence must be considered when using gross fluorescence as a direct indicator of bacterial numbers in the SdFFF technique for quantifying bacterial biomass. Moreover, they have serious implications for the application of fluorescence techniques in other instrumental approaches for bacterial enumeration in environmen

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01162.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

L. DOCHERTY, M.R. ADAMS, P. PATEL AND J. McFADDEN. 1996. A rapid and sensitive technique, based on the magnetic immuno‐polymerase chain reaction assay (MIPA), was developed for the detection ofCampylobacter jejuniin milk and chicken products. Target bacteria are captured from the food sample by magnetic particles coated with a specific antibody and the bound bacteria then lysed and subjected to PCR. The MIPA could detect 420 cfu g‐1of chicken after 18 h, 42 cfu g‐1after 24 h, and 4.2 cfu g‐1after 36 h enrichment. For artificially contaminated milk 63 cfu ml‐1could be detected after 18 and 24 h and 6.3 cfu ml‐1after 36 h

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01163.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

K. HAYASHI, M. INOUHE, C. AOYAGI AND D.J. NEVINS. 1996. A simple but accurate method for measuring glucuronoxylan xylanohydrolase activity was developed using coleoptile cell wall particles prepared from maize (Zea maysL.). Two isozymes of glucuronoxylan xylanohydrolases designated as GX1 and GX2 (EC 3.2.1.136) were purified from a commercially available amylase preparation to electrophoretic homogeneity by three cation exchange chromatography steps. Upon characterization no significant differences between the two enzymes were detected: the molecular mass measured by MALDITOF mass spectrometry was 44 360 100 for GX1 and 44 370 50 for GX2 suggesting no difference in the total number of amino acid residues. Furthermore theN‐terminal amino acid sequence for each of the isozymes was identical through the 37th amino acid residue. The values of pI were determined to be 9.0 for GX1 and 9.1 for GX2. The sensitivity to temperature, pH and to ionic strength was similar for both isozymes as were kinetic parameters includingKmandVmaxm No differences could be detected in substrate specificit

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb01164.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY