摘要:

Heat resistance data forListeria monocytogenesare reviewed. The organism is appreciably more resistant than commonSalmonellaserotypes but less resistant thanSalmonella senftenberg775W. Reports that the organism can survive heating at 80°C have not been substantiated and are incompatible with carefully determinedDandzvalues in milk and a range of foods. Cooking food to an internal temperature of 70°C for 2 min is adequate to ensure destruction ofL. monocytogenes.Normal pasteurization procedures will inactivateL. monocytogenesin milk but the margin of safety is greater for vat pasteurization than for high temperature short time treatmen

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00298.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Gradient plates provide a convenient means of assessing the effect of sodium chloride and pH in combination with different temperatures on the growth of microorganisms. The effects of these variables on the growth ofListeria monocytogenesin gradient plates at four temperatures are compared with growth in a micro‐well system. The growth‐limiting conditions in the two systems are in good agreement, and also compare favourably with data in the literature. The gradient plates gave a good illustration of the concentrations of sodium chloride required to inhibit growth at different temperatures and pHs, although incubation time is limited to 7

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Two different clones expressing endogluconase activity were isolated from a plasmid gene bank constructed fromRuminococcus albusSY3 genomic DNA. Hydrolysis of xylan and lichenan by cell‐free extract prepared from one of the clones may be attributable to a multifunctional protein. DNA hybridization demonstrated the absence of homology between the two endogluconase genes and a number of cellulase‐related genes cloned previously fromR.albu

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Citral showed appreciable antimicrobial activity against Gram‐positive and Gram‐negative bacteria as well as fungi. Media composition and inoculum size had no observable effect on activity but alkaline pH increased citral activity. The growth rates ofEscherichia colicultures were reduced at concentrations of citral ≥0·01% v/v while concentrations ≥0·03% v/v produced rapid reduction in viable cells followed by limited regrowth. In a non‐growth medium, 0·08% and 0·1% v/v showed rapid bactericidal effects. Citral may therefore be of preservative use in addition to its other uses in the food, soap and cosmet

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Agar strips containing glucose, xylose, cellulose, xylan and cysteine‐HCl were incubated in the rumen for 24 h. Fungal zoosporangia that developed on the strips were counted in calibrated fields. The results were expressed per unit area to provide an estimate of the relative size of the fungal population. Increases in fungal population size after defaunation were detected by this metho

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Forty strains ofBacillus sphaericusfrom major DNA homology groups and five strains pathogenic for mosquito larvae were examined for the ability to use 66 carbon and energy substrates. A medium based on triphenyl tetrazolium chloride gave highly reproducible test results. Only 13 substrates gave differential results. There was some correlation between established DNA homology groups and nutritional profiles, in particular mosquito pathogenic strains could be distinguished fromB. sphaericus sensu strictoby their ability to use adenine as a sole source of carbon.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00303.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Book reviewed in this article:BasicBiotechnology. A Student'sGuide(1987). Edited by P. Prave, U. Faust, W. Sittig&D.A. Sukatsch.BacteriaAS PlantPathogens(1987). By Eve Billing.Biotechnology.A ComprehensiveTreatiseIn8 Volumes.CurrentTopicsInMicrobiologyAndImmunology136: TheMolecularBiologyOfBacterialVirusSystems(1988). Edited by G. Hobom&R. Rott.GeneticBiochemistry: FromGeneToProtein(1988). By J. Etienne‐Decant.IntracellularBacteria: CurrentTopicsInMicrobiologyAndImmunologyNo.ProceedingsOfThe8TH InternationalBiotechnologySymposiumParis1988 (1989). Edited by G. Durand, L. Bobichon&J. Florent. Vol.BiologicalWasteTreatment(1989). Edited by A. Mizrahi.InVitroTechniquesInResearch(1989). Edited by J.W. Payne.BloodstreamInfections: LaboratoryDetectionAndClinicalConsiderations(1989). By C.L. Strand&J.A. Shulman.Metal‐MicrobeInteraction(1989). Edited by Robert K. Poole&Geoffrey M. Gadd.BiochemistryOfAntimicrobialAction(1989). By T.J. Franklin&G.A. Snow.TheoryAndApplicationOfMicrobialAssay(1989). By W. Hewitt&S. Vinc

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1989.tb00304.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY