Characterization of a protease of a feather-degrading Microbacterium species

Abstract

Aims: To characterize a new feather-degrading bacterium. Methods and Results: The strain kr10 producing a high keratinolytic activity when cultured on native feather broth was identified as Microbacterium sp., based on phenotypical characteristics and 16S rDNA sequence. The bacterium presented optimum growth and feather-degrading activity at pH 7·0 and 30°C. Complete feather degradation was achieved during cultivation. The keratinase was partially purified by gel filtration chromatography. It was optimally active at pH 7·0 and 55°C. The enzyme was inhibited by 1,10-phenanthroline, EDTA, p-chloromercuribenzoic acid, 2-mercaptoethanol and metal ions like Hg²⁺, Cu²⁺ and Zn²⁺. Significance and Impact of the Study: A new Microbacterium sp. strain was characterized presenting high feather-degrading activity, which appears to be associated to a metalloprotease-type keratinase. This micro-organism has enormous potential for use in biotechnological processes involving keratin hydrolysis.