Vol. 8, Issue 4 (2019)

Author(s):
MC Sanjana, B Ramachandra and R Prabha

Abstract:
Fresh raw milk, pasteurized milk and UHT milk samples obtained aseptically, after plating the fresh milk samples, and after the samples showed spoilage signs, enumerated to obtain biosurfactant producing Bacillus spp. by heating the samples to 800C for 10 min. to select spores of Bacillus species using sterile butter fat agar medium. The colonies that showed clear zone were considered as biosurfactant species of Bacillus. Among the milk samples enumerated, pasteurized milk fresh as well as spoiled showed a higher viable count of 3.16 and 4.57 respectively. Biosurfactant producing Bacillus species in raw milk were nearly the same as both in fresh and spoiled samples (3.12 and 3.43 log₁₀ cfu/ml). In Ultra High Temperature (UHT) milk, viable count of biosurfactant was absent in fresh sample and in spoiled showed a lower count of 2.24 log₁₀ cfu /ml. A total of 23 isolates showing clear zone on butterfat agar from fresh and spoiled milk samples were obtained based on colony morphology of Bacillus spp. and coded from B₁ to B₂₃ continuously. The isolates obtained from pasteurized and raw spoiled milk samples were 10 and 6 numbers. Accounting for 43.47 and 26.08 respectively.