EN
The aim of this study was to identify certain biochemical features in 691 B. cereus strains isolated from raw milk and the environment of milk production. At the first stage of the study the following abilities were observed in all the examined strains: the fermentation of D-glucose in facultative anaerobic conditions, the production of acetylmethylcarbinol (Voges-Proskauer reaction), the reduction of nitrates to nitrites, the production of acid from D-xylose, L-arabinose, D-mannitol and galactose, the hydrolysis of casein, gelatine and tributyrin and the ability of haemolysis. At the second stage, 142 chosen strains were subject to a detailed analysis of biochemical features with the application of API 50CH and API 20E tests (BioMerieux Polska Sp. z o.o.). The study confirmed the occurrence of the typical features for B. cereus as specified in Bergey’s taxonomy in all the examined strains: i.e. the ability of gelatine and casein hydrolysis, the fermentation of D-glucose, the production of acetoine, the reduction of nitrates to nitrites, and the lack of the ability of D-xylose and L-arabinose fermentation. 27% of the examined strains had an ability of lactose fermentation, which is untypical for B. cereus. 72% of the strains had the ability of tributyrin hydrolysis.