Hydrolysis of feather keratin by immobilized keratinase.

Keratinase isolated from Bacillus licheniformis PWD-1 was immobilized on controlled-pore glass beads. The immobilized keratinase demonstrated proteolytic activities against both insoluble feather keratin and soluble casein. It also displayed a higher level of heat stability and an increased tolerance toward acidic pHs compared with the free keratinase. During a continuous reaction at 50(deg)C, the immobilized keratinase retained 40% of the original enzyme activity after 7 days. The immobilized keratinase exhibits improved stability, thereby increasing its potential for use in numerous applications.