Biological Degradation of Keratin by Microbial Keratinase for Effective Waste Management and Potent Industrial Applications

Enzymes are the biocatalysts synthesized by living organisms having high specificity, catalytic activity, and a broad range of applicability. One such biotechnologically relevant enzyme is keratinase with various industrial applications that capture a significant place in the enzyme market. It belongs to the proteolytic enzyme group that cleaves the highly stable and fibrous protein, keratin through hydrolysis. Keratins are hard-degrading fibrous proteins insoluble in natural solvents and water. It is frequently aggregated in nature and expressively present in the plumes, hair, nail, horn, skins, feet, etc. The broad range of microorganisms, such as bacteria, fungi, and actinomycetes, have been accounted for producing keratinases with significant biotechnological applications. Successful application of this group of enzymes has been seen in various industries such as farming, laundry detergent, cosmetics, animal feed, pharmaceutical, leather, and textile. Moreover, they have found remarkable usability in environment friendly waste management also. This paper focuses on the structure, sources, and various applications of this industrially important enzyme.