 This research paper examines the degradation process of keratin by Bacillus spCn2. It found that the bacteria expresses several proteases, including glutamyl transferase, which breaks down the disulfide bonds in keratin, and endopeptidases and exopeptidases, which further hydrolyze keratin into smaller peptids. Additionally, the keratin hydrolysate contains a large amount of soluble peptids and essential amino acids. This article was authored by Yu Honglai, Shiyun Wu, Zhe'an Liangjing, and others.