Progress in Microbial Degradation of Feather Waste

Feathers are a major by-product of the poultry industry. They are mainly composed of keratins which have wide applications in different fields. Due to the increasing production of feathers from poultry industries, the untreated feathers could become pollutants because of their resistance to protease degradation. Feathers are rich in amino acids, which makes them a valuable source for fertilizer and animal feeds. Numerous bacteria and fungi exhibited capabilities to degrade chicken feathers by secreting enzymes such as keratinases, and accumulated evidence shows that feather-containing wastes can be converted into value-added products. This review summarizes recent progress in microbial degradation of feathers, structures of keratinases, feather application, and microorganisms that are able to secrete keratinase. In addition, the enzymes critical for keratin degradation and their mechanism of action are discussed. We also proposed the strategy that can be utilized for feather degradation. Based on the accumulated studies, microbial degradation of feathers has great potential to convert them into various products such as biofertilizer and animal feeds.