1 Scope
This standard specifies the method to examine bacillus cereus in food.
Method I in this standard is applicable to the counting of bacillus cereus in the food with high bacillus cereus content; Method II is applicable to the counting of bacillus cereus in food with low bacillus cereus content.
2 Apparatuses and Materials
Besides the conventional sterilization and cultivation apparatuses in microbiological laboratory, other apparatuses and materials are as follows:
a) Refrigerator: 2℃~5℃;
b) Constant temperature incubator: 30℃±1℃, 36℃±1℃;
c) Homogenizer;
d) Electronic balance: with sensibility of 0.1g;
e) Aseptic conical flask: with volume of 100mL and 500mL;
f) Aseptic suction tube: 1mL (with the scale division of 0.01mL), 10mL (with the scale division of 0.1mL) or micropipettor and suction head;
g) Aseptic petri dish: with diameter of 90mm;
h) Aseptic test tube: 18mm×180mm;
i) Microscope: 10×~100× (oil lens);
j) L-type coating rod;
3 Medium and Reagents
3.1 Phosphate buffer solution (PBS): see A.1 of Appendix A.
Foreword I
1 Scope
2 Apparatuses and Materials
3 Medium and Reagents
4 Plate Count Method (Method I) for Bacillus Cereus
5 MPN Counting Method (Method II) for Bacillus Cereus
Appendix A Culture Media and Reagents
Appendix B Retrieval of Most Probable Number (MPN) of Bacillus Cereus
