Probiotic characteristics, whole-genome sequence analysis of Bacillus with high collagenase production and its fermentation hydrolysis of cowhide

In this study, strains with high collagenase producing enzyme production were isolated from traditional naturally fermented foods rich in collagen. The safety of these strains was evaluated through in vitro biological characteristics and whole-genome sequence analysis. The results indicated that strains HA3, HA5, HA7, and HA8 exhibited high collagenase production, lacked hemolytic activity, and were sensitive to most commonly used antibiotics. Comprehensive analysis of antibiotic resistance genes, virulence factor genes, and metabolic systems at the genomic level confirmed the safety of these four strains, which were identified as B. spizizenii HA3, B. velezensis HA5, B. safensis HA7, and B. velezensis HA8, respectively. Notably, B. velezensis HA5 and B. velezensis HA8 could completely degrade cowhide into a liquid state and the antioxidant activity of the resulting fermentation degradation liquid was evidently improved. This study provides theoretical support and technical reserves for the development and utilization of livestock and poultry skins.