摘要:

Summary:The elements Mn and Fe, both alone and together, had a marked effect on growth and bulbiformin production byBacillus subtilis.Copper, with Fe and/or Mn had a deleterious effect on antibiotic production, whereas Cu+Zn as well as Mo+B slightly increased the antibiotic produced over that obtained with Fe+Mn. The optimum requirement of Fe was 20 p/m for both growth and antibiotic activity. The requirement of Mn for maximum growth was higher (2 p/m) than that for antibiotic activity (1 p/m).

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03668.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:This review summarizes the work on the subject carried out mainly in the authors’laboratories but also in the associated laboratories of Metal Box Co. Ltd., London, and Plat Manufaktor, Malmö, Sweden. Special attention is paid to the mechanism of bacterial reinfection and how it is influenced by deviations in can construction or can handling procedures. Methods of preventing bacterial reinfection at the most critical points in the canning operation are considered and certain guiding principles are deriv

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03669.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Preliminary results on a technique for identifying bacteria by spectrophoto‐fluorometry are presented. The 3 parameters involved, emission wavelength, excitation wavelength and intensity, are used to produce a topographic map characteristic of the fluorescence of the chemical bonds. Enhancement of the differences between species is possible using dyes such as acridine orange. Various improvements in the technique are presente

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03670.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:A method is outlined wherebyMycoplasmaspecies growing in broth culture can be rapidly counted, using the relationship between the number of organisms and the mean lactate dehydrogenase (LDH) content of each organism. The uses of this technique are discussed.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03671.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Strains ofAspergillus flavusrecently isolated from coconut products were cultured on grated coconut. The aflatoxin content of serial cultures was found to vary significantly with duration of incubation and for some strains to show more than one phase of increase of aflatoxin content. The occurrence of these variations indicates that the study of aflatoxigenic capacity of strains or of the capacity of a medium to support toxin production, should be based upon a knowledge of the pattern of variation of toxin content with duration of incubation of the cultures under the experimental conditions used. Assay of toxin level in a culture after one period of incubation could lead to erroneous conclusions about the identity or quantities of toxin components which the strain is able to produce.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03672.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Disposable plastic hypodermic syringes were taken weekly from commercial production, immediately prior to radiation sterilization, at each of 3 firms. They were irradiated at doses less than that used for sterilization, either with electrons or gamma rays, and tested for sterility. The relationship between the dose applied and the resulting proportion of syringes positive was similar for each firm. Amongst the organisms surviving subnormal process doses was a yeast of unusually high radiation resistance. The possibility of establishing a microbiological quality control procedure based on the routine use of a subprocess dose technique is discussed.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03673.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Glycerol stimulated sporulation ofSaccharomyces cerevisiaeHanson, especially when the cells were precultured in a complex growth medium instead of a chemically defined medium. Optimum spore yields occurred with 1–4% of glycerol but some were produced in 16% glycerol. Sporulation in glycerol was much less sensitive to ammonium sulphate inhibition than it was in acetate. Growth occurred with glycerol as sole carbon source and glutamic acid as sole nitrogen source, but not with ammonium sulphate as the sole nitrogen sourc

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03674.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Comparable results were obtained with a commercially available disposable system for the production of H2and CO2in an anaerobic jar (the Gaspak system) and with a standard anaerobic jar procedure. Both systems were used with the Baird&Tatlock anaerobic jar and a room temperature catalyst. The test organisms included strict anaerobes such asClostridium oedematienstype D andCl. tetani.Comparative tests were also made withBacteroidesspecies from laboratory stock cultures and with freshly isolated strains ofBacteroides.On occasion, higher recoveries were obtained with the standard system when relatively demanding models were set up but it has limitations, having been developed initially for research purposes. The Gaspak system probably gives more reliable and more reproducible results in a laboratory in which experience with strict anaerobes is limited or sporadic.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03675.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:Although extracellular accumulation of 5′‐nucleotides in streptomycetes is usually scarce one organism (772) formed considerable quantities of flavour‐enhancing 5′‐mononucleotides. A number of fermentation parameters were examined. Manganese ions, barbiturates and antibiotics appreciably affected the accumulation of such nucleotides. A 4‐fold increase in the formation of 5′‐inosinic acid was achieved by incorporating barbiturates in the medium, while substantial amounts of 5′‐guanylic acid could be also detected in presence

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03676.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Summary:The construction and operation of an apparatus for dosing laboratory fermenters semicontinuously with suspensions is described. The apparatus periodically measures a volume of slurry and then injects it into the fermenter. A control unit determines how often the cycle of operations is performed.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1972.tb03677.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY