Mutagenesis and Immobilization of ChitB-Protease for Induced De-staining and Goat Skin Dehairing Potentialities

Abstract

Proteases with alkaline nature and requisite catalytic characteristics have been the supreme interest of numerous industrial sectors. The present study was focused on justifying the following aims, i.e., (1) protease producing strain improvement via physical and chemical mutagenesis, (2) protease optimization, purification, and immobilization on chitosan beads, and (3) de-staining and goat skin dehairing potentialities of chitosan beads immobilized protease (ChitB-protease). Briefly, a protease produced by a UV mutant Bacillus sp. MS1 was purified and characterized to present its scope for detergent and leather sectors. Two-step purification resulted up to 4.1-fold purification and 41% yield of Bacillus sp. MS1 protease. The purified fraction was identified as a monomeric with an apparent molecular weight of 28 kDa on sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The protease was entrapped in glutaraldehyde-activated chitosan beads to improve its stability and reusability. The ChitB-protease represented the highest activity and immobilization efficiency of 10.31 U/mL and 86.43 ± 1.15%, respectively. ChitB-protease exhibited better catalytic activity in a broader pH range and higher temperature than free enzyme. Moreover, a significant improvement in the thermal resistance was also recorded after immobilization. ChitB-protease retained 70.53% of its initial activity after seven washings. SEM morphological analysis further confirmed the recycling efficiency of ChitB-protease. Furthermore, a complete de-staining and dehairing were observed within the short incubation period. These results suggest that this protease is potentially useful in many industrial applications.