Production and Applications of Keratinases in Industry

Abstract

Keratin is an insoluble protein with fibrous structure. It is mainly found in hair,feathers,nail,wool and horn of various animals. These animal accessories can be utilized as animals feed, amino-acids and fertilizers. This insoluble protein is very difficult to degrade and has extreme stability because it has disulfide bonds, hydrogen and hydrophobic interaction present in it. But keratin can be easily digested by keratinase enzyme. Keratinase is an extracellular enzyme. It also degrades keratin in prokaryotic organisms. Microorganisms that produce keratinase are species of Bacillus, Actinobacteria and fungi. It can also be obtained from Streptomyces, Aspergillus, Fervidobacterium, Xanthomonas, Chryseobacteriumand Vibrio. Keratinases produced by microbes arevery diverse due to their chemical as well as physical properties. It is a vigorous enzyme that can survive broad pH and temperature. Their optimum pH range is neutral to alkaline and their optimum temperature reported is 40°C to 60°C. And thermophiles have also been reported for stable microbial activity. Microbial keratinases are cheaply available as compared to conventional producers for keratinases production. They have gained great significance in biotechnology by acting on strong, inflexible cross linked polypeptide structure of keratin instead of ordinary proteolytic enzyme papain, trypsin or pepsin. They are mostly extracted by degrading keratin as substrate. Keratin substrates include feather, hair, wool,horn and nails. This degradation process is helpful in converting keratinous wastes in to fertilizer and poultry feed. Other renowned biotechnological implementations include removing hair from leather by using keratinase, development of bio-polymer from keratinous fiber, delivering drug, hydrolysis of prion proteins and detergent industry. They are also used in converting biomass in to biofuel that significantly boosts power preservation and recycling. The main problem for producing enzymes on large scale is their costly production procedures. This hurdle is overcome by utilizing keratin waste eg feathers of chicken as fermentation substrate on industrial scale. The benefit of utilizing this left over is extremely cost effective fermentation process of keratinase and the effluents are environmental friendly. Keratinase enzyme has become popular and provided newly effective and efficient way for managing waste products by using them on industrial scales as substrates which gives rise to environmental friendly industries for nonstop development.