Occurrence of Bacillus cereus and Bacillus licheniformis strains in the course of UHT milk production

• Published in: Czech Journal of Animal Science Vol. 47; no. 5
• Main Authors: Vyletelova, M. (Vyzkumny Ustav pro Chov Skotu, Rapotin (Czech Republic)), Svec, P, Pacova, Z, Sedlacek, I, Roubal, P
• Format: Journal Article
• Language: English
• Published: 01.05.2002
• Subjects: ACETOIN; ACETOINA; ACETOINE; ALMACENAMIENTO; ARN RIBOSOMAL; ARN RIBOSOMIAL; BACILLUS CEREUS; BACILLUS LICHENIFORMIS; BETA GALACTOSIDASA; BETA GALACTOSIDASE; BIOCHEMICAL POLYMORPHISM; CELLOBIOSE; CELOBIOSA; CHLORURE DE SODIUM; CITRATE; CITRATES; CITRATOS; CLORURO SODICO; COW MILK; CREAM; CRECIMIENTO; CREMA; CREME; CROISSANCE; GROWTH; HAEMOLYSIS; HEMOLISIS; HEMOLYSE; HIDROLASAS; HIDROLISIS; HYDROLASE; HYDROLASES; HYDROLYSE; HYDROLYSIS; LAIT DE VACHE; LAIT PASTEURISE; LAIT UHT; LECHE DE VACA; LECHE PASTEURIZADA; LECHE UHT; MANITOL; MANNITOL; MILK TANKS; NUCLEIC PROBES; PASTEURIZED MILK; POLIMORFISMO BIOQUIMICO; POLYMORPHISME BIOCHIMIQUE; RIBOSOMAL RNA; SODIUM CHLORIDE; SONDAS NUCLEICAS; SONDE NUCLEIQUE; STOCKAGE; STORAGE; TANK A LAIT; TANQUES DE LECHE; TAXONOMIA; TAXONOMIE; TAXONOMY; TEMPERATURA; TEMPERATURE; UHT MILK; XILOSA; XYLOSE
• ISSN: 1212-1819

The aim of the study was to monitor the transfer of Bacillus cereus and Bacillus licheniformis strains from raw milk into UHT milk. The milk was sampled during the whole time of milk processing (one milk batch). Representative B. cereus and B. licheniformis strains were characterised and compared by ribotyping with EcoRI enzyme and a probe complementary to Escherichia coli 16S and 23S rRNA as well as by phenotyping. According to 26 phenotypical traits the B. licheniformis strains formed almost a homogeneous group. In contrast, B. cereus strains exhibited variable results in several tests. The hybridisation profiles divided the analysed strains into two groups in full accordance with their species classification. Band patterns of B. cereus strains showed similarities ranging from 77 to 97 %; this similarity values correlated with biochemical test results as well. B. licheniformis strains exhibited band pattern similarities from 82 to 100 %. The hybridisation profiles of B. licheniformis strains B79 (pasteurized milk) were absolutely identical. Their phenotypical test results were identical as well. These results imply the identity of the strains isolated in the course of UHT milk production.