Screening and identification of a new Bacillus strain producing keratinase
角蛋白酶生产菌株的分离筛选与鉴定

Abstract: Objective] New wild strains, which were endowed with an effective depilation as their abilities to produce keratinase, were isolated to develop the bio-deliplatory agent in the sulfur-free tanning. Methods] A polyphase screening method was used to obtain the high-yielding wild strains. In this method, the sewage sample was obtained from the specific circumstance where the raw hides were stored, and then enriched by adding the defatted wool power as an inducer in the medium. Furthermore, the strains were screened via assessing the ability of the depilation of their fermentation broth. Finally, the isolated strain was identified according to their morphological features, physiological and biochemical characteristics, automatic identification by Biolog system as well as phylogenetic analysis of 16SrDNA sequences. Results] A higher activity and remarkable dehairing capability with sulfur-free was obtained. The results of identification indicated that the strain X-47 was the most closely related to Bacillus licheniformis, so it was named Bacillus licheniformis X-47. Conclusion] The wild strain Bacillus licheniformis X-47 was isolated successfully by the method of polyphase screening. It had a high keratinase-producing activity, high efficient of depilation and weak effect on collagen, which suggested that it has a considerable potential of developing the sulfur-free bio-depilation product.