ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00665.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Four pre‐enrichment media (nutrient broth, lactose broth, reconstituted non‐fat dry milk and nutrient broth containing 5% (w/v) casein) were evaluated for the recovery of salmonellae from cocoa powder. Addition of 5% cocoa powder to nutrient broth and to lactose broth proved to be bactericidal to salmonellae. Heat‐damagedSalmonella typhimuriumwere more sensitive than undamaged cells to cocoa powder and agitation increased the bactericidal effect. The bactericidal effects were minimized in pre‐enrichment media that contained either 5% casein or nonfat d

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00666.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The single‐celled algaChlorella vulgariswas cultured in the liquid phase of pig slurry under two different light intensities, and the development of the indigenous bacterial flora was compared qualitatively and quantitatively with that of controls not inoculated with chlorella. Particular attention was given to the occurrence and survival of potential pathogens. Algal growth was found to favour the growth of certain bacteria but had little effect on or was hostile to that of others. The effects of light were mediated by the algae rather than having a direct effect on the bacterial cells. The algae, which were harvested by centrifuging and then freeze‐dried, were found to enhance the survival of certain bacteria during this proced

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00667.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Occupational debris from beneath the Roman fort Vindolanda, and lake sediments cored from Seamere in East Anglia were examined for the presence of viableThermoactinomycesendospores. Up to 104viable endospores/g dry wt were recovered from the occupational debris at Vindolanda deposited between 1850 to 1890 years ago. Highest numbers were found in layers of bracken and straw litter sandwiched between clay floors within a military building. Associated artefacts and writing tablets have been used to date the various layers. Pollen analyses on core samples from Seamere revealed one region containing a declining percentage of tree pollen and the appearance of cereal and associated weed pollens suggesting the presence of a primitive agricultural community on the shores of the lake. Samples from this section of the core, depositedca. 1950 to 2750 years ago, contained viable thermoactinomycete endospores. These studies confirm the extreme longevity of Thermoactinomycete endospores and suggest that these organisms may be usefully employed in future archaeological and palaeoecological studies.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00668.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

In this study a comparison was made of recovering bacteria from stainless steel, plastic, wood, agar and meat surfaces. Sampling was performed using the agar contact and swab methods. The results indicated that for a flat, firm surface the contact plate method was more suitable, considering both recovery and repeatability. Swabbing was, by contrast, better for flexible and uneven surfaces and for heavily contaminated surfaces. Bacteriological guidelines are suggested for the hygienic evaluation of surface contamination of meat carcasses and for working surfaces in meat processing plates.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00669.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The location and formation of cellulases and β‐glucosidase in the fungusTrichoderma viridewere studied on different substrates. The cellulases were found to be cell‐bound during active growth on cellulose, CMC, and cellobiose. On CMC, much CM‐cellulase was found cell‐free but sonication released cellulase from the washed mycelium. Analysis of the carbohydrates of the mycelial cell wall after hydrolysis revealed glucose, mannose, and galactose—the same carbohydrates as reported to be present in purified cellulase from the same organism. Glucose repressed the formation of both CM‐cellulase and Avicelase and cellobiose apparently the formation of Avicelase. Relatively little CM‐cellulase was formed on cellobiose but a straight line was obtained when a differential plot of CM‐cellulaseversus

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00670.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A simplified method for the production of pre‐reduced anaerobically sterilized media for the cultivation of strict anaerobes is describe

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00671.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Wheat straw was subjected to aerobic and anaerobic decomposition in suspensions of soil. The products of the aerobic process stimulated the root extension of barley seedlings, whereas the anaerobic fermentation yielded products which inhibited growth. Acetic acid was the phytotoxin present in the greatest amount.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00672.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Evidence of the source of carcass contamination of pigs at slaughter was obtained by determining presumptive coliform counts on faeces and on carcass surfaces, and comparing the O‐serotypes and antibiotic sensitivity patterns ofEscherichia colifrom both sites. All of the 16 pig carcasses from the slaughter line of a commercial abattoir were contaminated with presumptive coliform bacilli on most sites examined; the carcasses of six out of eight pigs slaughtered at the Meat Research Institute (MRI) abattoir were also contaminated, but only small numbers of coliforms could be detected on a few of the sites. The proportion of O‐serotypes ofE. colipresent in faeces which were also detected on carcass surfaces, indicating faecal contamination, varied between 0 and 8.6% in MRI slaughtered pigs but reached 66.6% in one group of commercially slaughtered pigs. O‐serotypes found on carcass surfaces but not in the faeces of the pigs, were used as an indication of environmental contamination and this was very evident in the commercially slaughtered pigs. A high proportion ofE. coliO‐serotypes in the gut were resistant to antibiotics and these were also often found on the carcass surface and, since the range of O‐serotypes in the pig is similar to that reported in man, the pig must be considered to be a potential reservoir of antibiotic resistantE. co

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00673.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The apparent dry‐heat resistance ofB. subtilisvar.nigerspores in contact with serum albumin, certain carbohydrates or lipids, was determined in an open test system. The resistance, in terms of D160‐value, was significantly increased by sucrose or serum albumin and decreased by glucose or fructose. The D160‐value of spores heated in contact with olive oil and triolein was about the same as that of the control spores (clean spores). The D160‐value of spores in soybean oil, tricaprin or trilaurin was, however, somewhat higher than that of the control spores. The D160‐value for spores heated in different lipids increased in the order: olive oil

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1977.tb00674.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY