1984 Volume 25 Issue 2 Pages 106-111_1
The distribution of B. cereus in 302 samples of domestic skim milk powder was surveyed, and the results obtained were as followed.
1. Total bacterial counts were less than 300 per gram in 91% of the samples examined.
2. B. cereus was isolated from 10.3% of samples and other isolates were classified as Bacillus sp. The isolation rate of B. cereus among all isolates was 8.2%. The B. cereus counts in positive samples were mostly less than 300/g.
3. Among B. cereus isolates, 63% showed starch hydrolysis ability, while 37% did not.
4. We identified 30% and 28% of B. cereus isolates as Biotype 2 and Biotype 4, respectively, by means of Jinbo's method while Biotype 6 accounted for 24%; 82% of isolates classified as B. cereus were included in these three types.
5. The dominant species of Bacillus isolated from skim milk was B. licheniformis (40.5%), followed by B. pumilus (17.3%), B. megaterium (11.1%), B. subtilis (10.0%), B. coagulans (9.5%) and B. cereus (8.2%).
