Thermostable and halotolerant keratinase from Bacillus aerius NSMk2 with remarkable dehairing and laundary applications

Keratinases hydrolyze structural protein called keratin into constituent peptides. The present study reports excellent washing efficiency and dehairing properties of thermostable and halotolerant keratinase from Bacillus aerius NSMk2. Alkaline keratinase with molecular mass of 9 kDa displayed remarkable thermostability. K+ , Na+ , Ca2+ , Mn2+ , β-mercaptoethanol, sodium sulfite, dithiothreitol, ethanol, isopropanol, Tween-20, and Tween-80 stimulated keratinase activity, while Hg2+ and Ba2+ were found to be inhibitory. The enzyme efficiently hydrolyzed a variety of complex protein substrates and exhibited high catalytic efficiency toward keratin-rich substrates and least toward collagen. Keratinase showed exceptional stability to salinity and was found to be compatible with most of the commercial detergents. Efficient removal of chocolate, blood, and egg albumin stains from clothes and tolerance to elevated temperature and salinity potentiated the suitability of keratinase from B. aerius NSMk2 as laundary additive. Keratinase could efficiently dehair goat skin after 15 hr of incubation without damaging the grain structure and collagen layers that assures its use as a promising contender for leather industry.