Characterization of Bacillus Species Isolated from Pasteurized Milk*

Sixty pasteurized milk samples were collected aseptically from different processing dairies and analyzed for total viable count and aerobic spore count. Bacillus subtilis was found to be the predominant aerobic spore former (33.33%) followed by B.megaterium (24.44%), B.licheniformis (17.77%), B.cereus (8.88%), B.coagulans (6.66%), B.pumilus (4.44%), B.sphaericus (2.22%), and B.circulans (2.22%). The total viable count (log 10 cfu per ml) varied between 4.18 ± 0.095 and 4.43 ± 0.081 among nine different processing dairies and it was the lowest in lab-pasteurized samples (3.65 ± 0.078). The mean aerobic spore count (log 10 cfu per ml) varied between 3.56 ± 0.051 and 3.87 ± 0.112 among the processing dairies and the lowest values were obtained in lab pasteurized milk samples at 3.09 ± 0.085. Out of forty five Bacillus species isolated, twenty five isolates were positive for proteolysis and seventeen for lipolysis and twelve isolates for both proteolysis and lipolysis.