A review: Potentials for biotechnological applications of keratin-degrading microorganisms and their enzymes for nutritional improvement of feathers and other keratins as livestock feed resources

Advances in microbial enzyme technology, keratinolytic proteases in this case, offer considerable opportunities for a low-energy consuming technology for bioconversion of poultry feathers from a potent pollutant to a nutritionally upgraded protein-rich feedstuff for livestock. A compendium of recent information on microbial keratinolysis in nature and infection (dermatophytoses) has been provided as underscoring feasible harnessing of the biotechnology for nutritional improvement of feathers, and as an alternative to conventional hydrothermal processing. Supporting evidence of a nutritional (amino acid) upgrading sequel to diverse microbial treatments of feathers, and positive results obtained from growth studies in rats and chicks have been presented. The paper concludes with suggestions for avenues of application of biotechnology for nutritional improvement of feather (and other keratins) as feedstuffs for livestock. (C) 1998 Elsevier Science Ltd. All rights reserved.