DECOMPOSITION OF NATIVE KERATIN BY <i>STREPTOMYCES FRADIAE</i>

Abstract

Keratin, by virtue of its insolubility and resist-ance to proteolytic enzymes, is not attacked by most living organisms. Nevertheless, keratin does not accumulate in nature and, therefore, bio-logical agencies may be presumed to accomplish its removal. Several insects, including clothes moth larvae, carpet beetles, and chewing lice are known to digest keratin (Waterhouse, 1957). The common occurrence in nature of micro-organisms that readily and, in some cases, prefer-ably grow on keratinaceous substrates has supported the general belief that certain micro-organisms can digest keratin. Classical examples of such microbes are the parasitic dermatophytes and the saprophytic Onygena equina (Ward, 1899). In addition, the literature contains numer-our reports that the ability to decompose keratin is possessed by various other microorganisms, e.g., members of the genus Ctenomyces (Sen