市販むき身カキにおける低温性大陽菌群の分布

概要

論文の詳細を見る
Eighteen samples of commercial shucked oyster including 12 samples graded “for cooking” and 6 “for eating raw” were collected from department stores in Tokyo and analyzed bacteriologically. Presumptive coliform counts were obtained by enumerating typical red-coloured colonies formed in the desoxycholate agar plates after 24hr incubation at 30°C, and the counts obtained ranged from 6.6 to 2.2×103 per g. According to the IMViC (indole, methyl red, Voges-Proakauer, citrate), motility and gelatine liquefaction tests, 149 coliform isolates were classified into 21 types, each of which was subdivided into 6 groups on the basis of growth ability at 5 and 40°C. Of these coliform isolates only 3 types, Type 1 (--+++-), Type 2 (--++++) and Type 5 (-+-++-) accounted for 68.5% of the total. The remaining 18 coliform types occurred in small percentages of less than 5% respectively. On the other hand, 75.8% of all coliform strains were able to grow at 5°C within 10 days and these psychrotrophic coliform organisms were considered to be of natural environmental orgin. On the contrary, it was shown that typical mesophilic coliforms of human and warm-blooded animal origin contributed a relatively small perentage among the total coliforms isolated from shucked oyster samples.
公益社団法人日本水産学会の論文