Isolation, purification and mass production of protease from Bacillus subtilis

Isolation and identification of protease producing strains of bacteria were carried out from four different soil samples collected from various places in Tiruchirappalli. The organisms were tested by various biochemical tests, which led to their identification as Bacillus subtilis producing protease enzyme. These Bacillus subtilis could grow up to 60oC and in pH range of 6-9 with optimal growth temperature and pH of 55oC and 9.0 respectively. It was also optimized for carbon test and nitrogen test with optimal growth in dextrose and peptone respectively. Enzyme production was carried out in 1 litre of optimized media in the fermenter at 55oC for 48 hours at pH 9.0. Harvested protease product was purified by salt precipitation method. Finally the enzyme protease was purified by column chromatography. The protein was characterized using SDS-PAGE. This result showed that Bacillus subtilis is a good producer of extra cellular protease. The enzyme produced by B. subtilis is pH stable and thermo stable, which can be utilized in local detergent and leather industry.