摘要:

A grass + fishmeal ruminant feed was incubated for 7 d in a mineral salts medium with the non‐proteolytic rumen bacteriaBacteroides succinogenes, Ruminococcus flavefaciens, Megasphaera elsdeniiand proteolytic strains ofBacteroides ruminicola, Selenomonas ruminantiumandStreptococcus bovisin the presence and absence of the anaerobic fungusNeocallitnastix frontalis. The fungus increased the dry matter digestion from 65·0 to 69·4%, and more than doubled the proteolytic activity of the culture filtrate. However, a greater difference was observed with the solid material, where the proteolytic activity increased from 0·71 to 6·89 mg14C‐casein hydrolysed/g/h, due mainly to EDTA‐sensitive fungal

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01539.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Four species ofStreptomyces, Streptomyces canescens, S. limosus, S. griseusandS. griseolus, were used to study the effects of glycerine and gelatin on the formation and regeneration of protoplasts. For each species efficient protoplast formation with high protoplast concentrations and low levels of non‐protoplast units was obtained with mycelia grown in medium without glycerine. The low regeneration frequencies of protoplasts ofS. canescensandS. limosuson R2 medium were increased substantially by the addition of 1% gelatin. The use of single colonies, rather than spores, to establish mycelial cultures was found routinely to produce good protoplast preparation

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01540.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Three proteins, named P1, P2 and P3, were separated from purifiedClostridium perfringensenterotoxin by high performance liquid chromatography (HPLC) on a DEAE‐5PW column. The relative biological activities of P1, P2 and P3 on protein basis determined by the African green monkey kidney (Vero) cell staining assay were 3·0, 1·9 and 1·0, respectively. P1, when trypsinized and re‐chromatographed, revealed the same HPLC pattern as that of untrypsinized P1, but a new peak, P2′, emerged from P2 and P3 after trypsinization, by HPLC. The relative biological activity of trypsinized P1 was of the same level as that of untreated P1, but those of P2 and P3 increased one and a half to three times upon trypsinization and finally reached the same level as those of P1

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01541.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A phage K3‐resistant isolate fromEscherichia coliP678‐54 was devoid of both the OmpA and OmpC proteins but had high levels of the OmpF protein. Associated with these changes, the strain showed increased sensitivity to inhibition by detergents and greatly increased sensitivity to Cu2+. Introduction of the ColV, I‐K94 plasmid into this mutant produced a derivative with markedly increased resistance to Cu2+ions but unchanged detergent sensitivity. Analysis of membranes showed that the ColV, I‐K94+derivative had essentially no OmpF protein in its outer membrane. Aca36 K outer membrane protein was present which resembled the OmpC protein in size and failure to dissociate in SDS at low temperature. It was distinct from the OmpC protein, however, in failing to allow either tetracycline uptake or the adsorption of T4‐type phages. The possible significance of OmpF porin derepression (and its reversal by ColV, I‐K94) for enterobacterial survival in aquatic situations i

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01542.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

An antimicrobial removal device was used successfully in a sterility test on a viscous, non‐aqueous formulation containing streptomycin and benzylpenicillin. Conventional techniques such as dilution, enzymic inactivation and membrane filtration having failed, it is suggested that use of the devices be considered as an alternative to established procedures for sterility testing of antimicrobial preparation

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01543.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A computer program that facilitates the creation of a culture collection database has been written for a microcomputer (Apple He with a Z‐80 card) using dBASE II® (Ashton‐Tate). The Culture Collection Program accommodates up to 250 individual strain records on one 5 1/4″ floppy disk. For each strain, information that can be stored includes the name of the micro‐organism, culture collection number, antibiotic resistance markers, plasmids, genetic markers, references, growth medium, growth temperature and additional comments. The last date of subculturing can be ascertained and information about the status of the preserved cultures can also be noted. With a menu‐driven format which requires no computer programming expertise, the user can readily create new entries, update old ones and search the database for strains with certain common

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01544.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Fifty samples of retail goats milk were analysed for the total number of viable bacteria present and the incidence ofYersiniaspp. Both were found to be producerdependent. Overall, 26% of samples containedYersiniaspp. These were mainlyYersinia enterocoliticabutY. intermediawere also isolated. Pre‐enrichment of samples in trypticase‐soy broth (TSB) followed by selective enrichment in a bileoxalate‐sorbose medium was considerably superior to prolonged cold enrichment in TSB for the isolation ofYersin

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01545.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

One drawback of using two‐dimensional diffusion gradient plates, the subjective visual assessment of microbial growth, has been overcome. Growth ofEscherichia coliwas detected with pH indicators in the medium or by staining growth with a biochemical stain, L‐alanine‐p‐nitroanilide, or a respiratory dye, 2‐(p‐iodophenyl)‐3‐(p‐nitrophenyl)‐5‐phenyl tetrazolium chloride. Stained growth was scanned with a laser densitometer and traces combined in a computer to give a three‐dimensional semi‐quantitative representation of growt

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01546.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Twenty trypsin‐positive black‐pigmentedBacteroidesstrains independently isolated from periodontal lesions in sheep were characterized by Gram stain, biochemical tests, haemagglutination, gas liquid chromatography, API ZYM system profiles and catalase activity. All strains reacted uniformly in these tests, the reactions closely resembling those reported for human strains ofBacteroides gingiva

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01547.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY