摘要:

ABSTRACTThe influence of the microbial contamination load (xl) and preservative concentration (x2), as predictor variables, on the percentage of vials with growth of B. pumilus spores (y) was studied. The effect of a wide range of spore loads (1‐500,000 spores of B. pumilus per sample) and preservative (chlorhexidine acetate) concentrations (0.03–40 μg/ml) on the percentage of contaminated samples was determined. Each contamination load was studied by adding the specified number of spores to vials containing various concentrations of chlorhexidine dissolved in 2 ml of nutrient broth. Every level of spore and chlorhexidine concentration was represented by 50 or 100 vials. Curves representing the number of contaminated vials against the concentration of chlorhexidine were sigmoidal in shape and the data showed an indirect relationship. Data were analyzed by the regression analysis which revealed a significant correlation (R=0.83) with the regression equa

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00509.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTCommercially sterile garlic, sage, black pepper, cinnamon and clove were investigated as heat sensitizing agents towards Bacillus subtilis spores. Heat treatment at 80°C for 10 min of all spice‐spore mixtures (0.9 g spice/0.1 g spores) in distilled water (9 mL) reduced initial counts (106/mL) by approximately 0.5–1.0 logarithms, with the exception of garlic which showed no effect. The clove‐spore mixture exhibited the greatest reduction in survivor counts. Dry spice‐spore mixtures conditioned for 24‐96 h in relative humidities (RH) from 64 to 98% and at temperatures from 25 to 35°C, prior to heat treatment, exhibited additional reduction in survivors. The clove‐spore mixture exhibited the greatest decrease in heat‐treated survivors (approximately 4 logarithms) after conditioning at 96% RH and 35°C for 96 h. Relative humidity conditioning of cinnamon‐spore mixtures, regardless of treatment regime, did not reduce the number of heat‐treated survivors. Increasing the temperature and/or RH of conditioning for the remaining spice‐spore mixtures generally increased heat sensitization. Aw‐equilibrated spice‐spore mixtures which were not heat‐treated (controls) showed no reductions in viability. Moisture sorption by the spices during conditioning only partially influenced th

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00510.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThroughout the years numerous investigations concerning the inhibition of microorganisms by spices, herbs, their extracts, essential oils and various constituents have been reported. Many of these materials possess significant antimicrobial activity, which in many cases is due primarily to a particular constituent. Interpretation and comparison of results of various studies is complicated by variations in the methodology used for the determination of antimicrobial activity. The antimicrobial activity varies depending on the microorganism, the spice or herb and the test medium. These and other factors are examined in the light of their effect on the outcome of the test method.

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTYersinia enterocolitica heat‐stable enterotoxin (YST) was partially purified by ion exchange, gel filtration and Fast Protein Liquid chromatography. Infant mice given YST orally (p.o.) exhibited diarrhea 4 h after administration; a few infants died by 6.5 h. Pups dosed intraperitoneally (i.p.) and adults dosed p.o., i.p. and intravenously showed no symptoms during the 7 days of observations. Tissues of adult mice orally challenged with YST showed no pathological changes by light microscopy. Livers of infant mice orally dosed with YST showed evidence of severe glycogen depletion. The intestinal tracts of YST‐dosed (p.o.) infant mice exhibited severe pathological changes including: epithelial cell and villous tip necrosis, villous edema, and capillary and lacteal engorgement. Kidneys of YST‐dosed (p.o.) infant mice exhibited devacuolization of the proximal convoluted tubule cells which indicates metabolic inactivity and a probable decrease in the resorption of glomerular filtrate (protein, carbohydrate, electrolytes and w

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The effect of two sodium phosphate‐sodium chloride buffers (0.2 M, pH 7.4 and 0.05 M, pH 6.5) on the separation of staphylococcal enterotoxins from soluble proteins in foods was examined by ion exchange column chromatography. The microslide gel diffusion test, by which recovery was determined, was more accurately interpreted when lower ionic strength buffer was used. The procedure described here has been incorporated into the official method of the Association of Official Analytical Chemists for the separation of staphylococcal enterotoxins from food

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Book reviewed in this article.Modern Biotechnology.S. B. Primrose

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1988.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY