Development of semi-solid state fermentation of Keratinase and optimization of process by cheaper and alternative agricultural wastes
Ch. M kumari Chitturi, VV Lakshmi
Keratinases are largely serine or metallo proteases. They attack the keratin residues and find application in developing cost-effective feather by-products for feed, fertilizers, detergent and leather industries. In the present study semiSSF method for keratinase production using Bacillus sp. was developed that appears to be a viable and economic alternative of bioconversion of large quantities of feather. Keratinase production was highest with rice bran for MBF11 (318KU/ml), black gram for MBF20 (354KU/ml), green gram for MBF21 (374KU/ml), wheat bran for MBF45 (497KU/ml). Standardization of moisture content resulted in identifying optimum conditions of SSF with only 33% of the original moisture content. Keratinase yield was found to be higher in SSF as compared to SmF for MBF strains. Substrate concentration was found to influence keratinase yield between 1-4% for the four Bacillus strains with yields increasing from 283-367KU/ml to 415-442KU/ml.