Evaluation of Protease Production by a Halotolerant Bacillus megaterium (MTCC-9205) in Different Agro-Industrial Wastes Through Submerged Fermentation

Abstract

In the present study, a well characterized and identified halotolerant bacterial strain (Bacillus megaterium MTCC-9205) was evaluated for its protease production. The bacterial strain when grown in skim milk agar plates showed the conspicuous zone of clearance around the colony indicating the protease production ability. Evaluation of extra cellular protease production by the bacterium was conformed in skim milk broth medium. Both acidic and alkaline protease production by the bacterium was screened in the skim milk broth medium using different substrates such as whey, soybean powder, black gram, green gram, wheat bran as cheap carbon sources. The highest yield of alkaline protease of 38.47 ± 1.32 U/ml by the strain was observed during the fermentation with soybean powder along with higher biomass (0.487±0.24 g/50 ml) production. Similarly acid protease was found to be 46.75 ± 1.22 U/ml with soybean as carbon source. The fermentation kinetics as well as yield factor of alkaline protease production was calculated and found maximum (12.95 U/g) in presence of soybean powder as carbon source. Further, the strain is immobilized and the activity of the enzyme was studied up to fourth cycle. The activity of the enzyme increased slightly with the use of recycled beads up to third cycle and fell thereafter. Hence, the present study revealed that the halotolerant B.megaterium is a potential protease producing bacteria which can be exploited for various industrial applications.