Valorization of Feather Waste by Microbial Enzymatic Activity: Bioconversion, Production and Application

The recalcitrant heap of chicken feathers is one of the most hostile environmental pollutants. It has been estimated that about 8.5 billion tons of chicken feathers are discarded per annum globally, while India alone contributes 350 million tons in a year. These knave heaps of chicken feathers, being the high sources of proteins, contains about 90% (w/w) of β-keratin along with phenylalanine, glycine, arginine, glutamate and cysteine. Keratinolytic microorganisms often secrete a hydrolytic enzyme; keratinase that have the ability to degrade the disulfide and peptide bonds of keratin. Potent keratinolytic microorganisms can convert recalcitrant feather waste into protein hydrolysate which can be used to generate high-quality vermicompost. In addition, it can be effectively used in cosmetic sector, leather industry, textile industry or as livestock feed. It may also provide a sustainable alternative approach to produce renewable energy. The study aims to focus on different methods of valorization of feather waste by keratinolytic bacteria, bioconversion processes and widespread applications of feather hydrolysate.