Examination of the biochemical characteristics of bacilli isolated from raw milk
1998
Mijacevic, Z. | Bulajic, S. (University of Belgrade, Belgrade (Yugoslavia). Faculty of Veterinary Medicine)
Examination of 114 milk samples for the presence of bacilli, showed that bacilli occurred at different levels depending on the place where the samples were taken. Mean bacillus number in milk samples on the farm after milking was 0.92+-0.81 log/ml. In milk samples at the collection point, the mean bacillus number had increased to 1.52+-0.66, and remained at 1.56+-0.42 log/ml in big dairies. The number of bacilli in 114 samples was determined immediately the first day after treatment for 10 min. at 80 deg C, and after keeping the milk for 10 days at 7 deg C. It was found that some bacilli grew in psychrotrophic conditions. By t-test it was confirmed that the bacilli numbers increased or decreased significantly in different samples of milk. A high percentage of isolated bacilli multiplied at the temperature of 45 deg C (98.51) and 55 deg C (89.62), in the presence of 7 NaCl (92.59) and in broth at pH 5.7 (97.77). It was also found that 48.15 of isolated strains were haemolytic and 67.40 degraded lecithin, which indicates that the isolated strains are possibly pathogenic. Determination of the enzyme activity of isolated strains, showed that 80.74 degraded casein, 40.00 hydrolysed starch and 5.92 broke down gelatin. This enzyme activity of bacillus strains is significant for producing processes in the dairy industry.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Unassigned data from Yugoslavia