Studies on Alkaline Protease from Bacillus crolab MTCC 5468 for Applications in Leather Making

Bating has become an indispensable operation of leather making to obtain good quality leather. Alkaline proteases are commonly used in leather manufacture in the process of unhairing and bating of hides/skins. In this study, experiments were carried out to test the bating efficacy of a new alkaline protease obtained from Bacillus crolab MTCC 5468 and compared with commercial bate. Impact of alkaline protease on porosity of enzymatically and conventionally unhaired goat skins, have been compared. New enzyme treated pelt was free from scud and pigments, with fine, clean, white, silkier grain and pliable. The result was superior to that of commercial bate treated pelts. The pore size/distribution and water vapor permeability was better than commercial bate and conventionally unhaired skins. Scanning electron microscopy and histological analysis of pelt obtained from new alkaline protease based process reveals complete removal of scud and better opening up of collagen fibers. Moreover, the collagen was not damaged and resulted in good quality of leather. The physio-chemical studies conclusively show that among the experiments, the skins unhaired with new alkaline protease was better in comfort properties than the conventionally unhaired skins as inferred by porosity measurements. Using new alkaline protease for bating led to better results than commercial bate. The study indicates improved efficiency of bacterial alkaline protease in leather processing for beam house applications.