Production and purification of alkaline protease from bacillus subtilis mr12 isolated from slaughter house soil

Proteolytic bacteria were isolated from slaughter house soil with the help of Skim milk agar plates. The isolate showing maximum activity was selected and characterized based on Bergey’s manual. Upon 16S rDNA analysis, it displayed maximum similarity with Bacillus spp., and the sequence has been deposited in Genbank. For the production of alkaline protease, the strain Bacillus subtilis MR12 was grown on modified production medium containing sludge as substrate. Different cultural parameters were optimized for maximal enzyme production. Peak proteolytic activity was observed at pH-8.5 and temperature at 50 C with 1% inoculums. Cetrimide exhibited the highest inhibitory activity followed by Tween-80, SDS and Tween-20. Alkaline protease was purified to homogeneity by Q-Sepharose revealing a molecular weight of 35 kDa. The enzyme was active and more stable at pH-9 and 55 C.