摘要:

The effect of lytic enzyme treatment upon protoplast formation and reversion in three species ofActinomadurahas been determined. Incubation in the presence of lytic enzyme L2 generates large protoplasts (4 μm diameter) which remain intact for only 2h. In comparison, protoplasts formed by the degradative effects of the enzymes lysozyme and L1 are smaller (2 μm diameter), and remain stable for up to 18h. This results in a greater efficiency of regeneration. Lytic enzyme L2 has been shown to contain impurities, including proteolytic activity, which may affect cell wall regeneratio

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00210.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A centrifugation and filtration method of isolatingCampylobacterphages has been developed. Forty‐nineCampylobacterphages were isolated from 272 effluent samples of which 42 produced lysis withCampylobacter jejunistrains and seven with C.colistrains. Phages were recovered from pig manure, abattoir effluents, human faeces, sewage and poultry manure. Phages were not isolated from water samples, cattle and sheep faeces or farm pasture soi

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00211.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The beta‐glucosidase inThermomonspora curvatawas stabilized against thermal denaturation by a soluble intracellular factor. This factor had an apparent molecular weight of 6kD, was resistant to proteolytic digestion, stable to boiling but was inactivated by autoclaving. It had little effect on beta‐glucosidase maximal velocities or substrate affinity but it reduced the enzyme inactivation rate five‐fold at

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00212.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Escherichia coliUB1005 (DCO), an envelope mutant (DC2),Pseudomonas aeruginosa799 and an envelope mutant (799/61) were exposed to sodium deoxycholate (DOC), sarkosyl and sodium lauryl sulphate (SLS). DOC was the least effective lytic agent, but the twoPs. aeruginosastrains, especially 799/61, were more susceptible to DOC and sarkosyl than theE. coliones. SLS was an efficient lysing agent, although Ps.aeruginosa799 was the least susceptible of the four strains. DC2 was lysed more rapidly and to a greater extent than UB1005 by all three agents. The mutant strains, especially DC2, were more sensitive to selective media than the wild‐type one

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00213.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A red‐pigmented, radiation‐resistant, Gram‐negative, rod‐shaped bacterium isolated from irradiated pork is described. The D10values in buffer solution and on pork mince are 3·45 and 5·05kGy respectively. The strain has been identified as aDeinobact

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00214.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Two monoclonal antibodies conjugated to fluorescein isothiocyanate (FITC) were successfully used in a direct immunofluorescence test (DIFT) to demonstrate listeria in seven samples of soft cheese whereListeria monocytogeneshad been cultured by conventional techniques. Using DIFT, listeria was not detected in 20 cheese samples from whichL. monocytogeneshad not been isolated, or was present in low numbers (90% of strains ofL. monocytogenesisolated from food and cultured on Modified McBride agar or Blood agar. Less than 10% of strains of other species of listeria would be misidentified when grown on these media. All tests were carried out within 2 h.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00215.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Numbers of Bacteroidaceae, Enterobacteriaceae and staphylococci were higher in the periphery of the colonic contents of rats than in the core. Numbers of total anaerobic bacteria, lactobacilli and enterococci did not differ among these regions. Activities of glycosidases were higher in the periphery than in the core.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00216.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

By baiting litter soils with raw potatoes, species of bacilli producing thermostable amylases and raw starch‐degrading amylase were selectively isolate

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00217.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

By use of the radiolabelled substrates sodium [1–14C] acetate, sodium [2–14C] acetate, NaH14CO3and14CH3OH, three of the possible methanogenic pathways in fermenting refuse were confirmed. Due to the absence of a methanol pool, however, the relative contribution of each could not be determined. Circumstantial evidence for an operative trimethylamine pathway was gained but not confirmed whilst preliminary attempts to stimulate methanogenesis in refuse by supplementation with mono‐and dimethylamine proved unsucce

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00218.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY