ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Staphylococcus aureus is less sensitive to gamma radiation when suspended in fish homogenate or crab meat than in phosphate buffer. Comparative tests of various media confirmed that Staphylococcus No. 110 (Difco) plus egg yolk incubated at 45°C gave good recoveries of S. aurens from irradiated samples.The ability of S. aureus to survive and grow out in brain-heart-infusion broth, heat-sterilized crab meat, and unsterilized crab meat before and after irradiation was tested at various temperatures. The organism died out when stored at 1 and 8° regardless of treatment. At 12°C, S. aureus grew well in sterilized crab meat, reaching a count of 10° cells per gram after 14 days, but was greatly inhibited in nonsterile crab meat, whether irradiated or not. At 22° (room temperature), S. aureus grew well and rapidly in sterilized crab meat, reaching a count of 108 cells per gram within three days, but was inhibited or grew poorly in untreated (non-sterile) crab meat. Apparently the inhibition of growth was due to competition by saprophytic bacteria naturally present in crab meat. The effect of such competition was largely eliminated when crab meat was irradiated at 100 and 200 Krad and S. aurens grew out well in such material when incubated at 22°C. There was some evidence that the ratio of staphylococci to saprophytic bacteria influenced outgrowth, but the major effect seemed to be due to the creation of inhibiting conditions in crab meat by the competing bacteria since staphylococci were completely inhibited in spoiling erab meat samples even after irradiation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1965.tb00313.x
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