摘要:

The taxonomic status ofNocardia amaraestrains was examined using chemical, microbiological and nucleic acid sequencing methods. It was evident from the results of this and previous studies thatNocardia amaraehas properties that are at variance with its classification in the genusNocardiabut consistent with its transfer to the genusGordona. It is proposed thatNocardia amaraeLechevalier and Lechevalier 1974 be transferred to the genusGordonaasGordona amaraecomb. nov.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00967.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Fifty consecutive faecal specimens received by the LEP were examined for the presence of Vero cytotoxin (VT) genes by polymerase chain reaction (PCR) gene amplification. Nineteen were positive by PCR and from 16 of these, VT positiveEscherichia coliO157 were isolated. The remaining three samples were positive for VT genes by PCR but VTEC were not isolated. In a preliminary experiment,Shigella dysenteriaetype 1 was isolated from a case of bloody diarrhoea following a positive amplification result.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00968.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A novel extracellular β‐fructosidase produced byBacillus stearothermophilushas been identified and purified. The purified enzyme, obtained by using successive QEAE Sepharose fast flow and Sephacryl S300 HR columns, has a 600 kDa relative molecular weight (Mr) and is composed of 60 kDa subunits indicating a multimeric structure. The pH and temperature for optimal activity are 6.5 and 65°C respectively, the enzyme being thermostable at this temperature. The apparent Kmvalues for sucrose and inulin are 3.56 mmol l‐1and 1 mmol l‐1respectively, the total invertase/total inulinase ratio

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00969.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Growth of eight selected potentially pathogenic strains ofBacillus cereuswas evaluated in a rich medium at different temperatures. No strain grew at 50°C; maximal growth‐permissive temperatures were in the range 46–50°C for six strains and under 46°C for one strain. Faster growth occurred at 42°C. Growth may be delayed at 20°C, where the lag phase can reach 7 h. Furthermore at 20°C, cells generally show an aggregation immediately in the early exponential stage, except for two strains. Owing to this aggregation, growth is more difficult to estimate by turbidimetry at lower temperatures. These data describe the behaviour of type and field strains between 50° and 20°C and can help the prediction of shelf‐life of potentially contamin

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00970.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A strain ofSalmonella typhimurium, transformed to a bioluminescent phenotype, was used to compare three freeze‐drying suspension media: inositol serum broth with and without added gelatin and sterile skimmed milk. Recovery and growth studies performed by measuring changes in bioluminescence demonstrated that of the three media tested, the routinely used inositol serum broth was the most effective freeze‐drying suspension med

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00971.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Cyanobacterial hepatotoxins and anatoxin‐a, a neurotoxin, were shown to be degraded when crude extracts of lysed toxic laboratory strains of cyanobacteria were exposed to natural populations of micro‐organisms from lakes. While anatoxin‐a decayed equally fast with all the inocula from lake sediment and water, the degradation rate of hepatotoxins was higher with inocula from places at which cyanobacterial water blooms had occurred than with inocula from places with no known mass occurrences of cyanobacteria. Degradation was slowest when an inoculum from a humic lake was used. A part of the loss of the toxins was shown to be due to adsorption on lake sedi

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00972.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Cells ofListeria monocytogenesthat had been exposed to pressure contained vacuolar regions in the cytoplasm. Pressure‐treated cells ofSalmonella thompsoncontained no vacuoles but had fewer ribosomes than untreated cells and their appearance suggested that some cell lysis had occurred. In both organisms changes in the appearance of the nuclear material were observe

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00973.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Wistar rats fed diets containing different contents of cellulose or 5% transgalactosylated oligosaccharides (TOS) for 7 weeks were examined for faecal microflora and caecal short‐chain fatty acids. High (15%) cellulose diet showed remarkable increases in concentrations of faecal bifidobacteria and caecal butyrate with a reduced concentration of propionate as compared with the other diets. TOS‐fed rats showed strikingly increased concentrations of bifidobacteria and acetate. A comparison of pH values between the caecal contents and faeces suggested more fermentation of cellulose in the distal than proximal part of the large bowel of r

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00974.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Enterococcus faecaliswas the most frequently occurring enterococcal species in caeca and cloacal swabs of chickens in Assam, India. In chickens less than 8 weeks of ageEnt. faecium, Ent. duransand Ent. avium were also found, but infrequently.Enterococcus hirae, which is potentially pathogenic in chickens of less than 1 week of age, was found only in chickens of more than 8 weeks. Except for a higher frequency ofEnt. faecalis, the composition of this flora was essentially the same as that in European temperate climates.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00975.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AnEnterococcus faeciumstrain from Nigerian fermented skimmed cow milk (‘wara’) produced bacteriocin inhibitory towardsLactobacillus, EnterococcusandListeriastrains. The bacteriocin (designated enterocin 01) was inactivated by proteases, heat‐stable at 100°C and active at pH 2.0–6.0. TheEnt. faeciumisolate harboured plasmids ofca36.3 and 23.1 kb. Curing experiments with ethidium bromide resulted in a bacteriocin‐negative mutant which had not lost immunity to the bacteriocin. Slight differences in plasmid profiles between wild‐type and mutant indicated a possible plasmid‐coded bacterio

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00976.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY