Screening and identification of protease-producing strain for hydrolysis of rice dreg protein

Screening of protease-producing strains(PPS) was used for hydrolysis of rice dreg protein(RDP),which could promote green development and make full use of RDP. A total of 115 PPS were isolated from samples protein-rich by casein plate method. These PPS were cultured with RDP as sole carbon and nitrogen source. Then,one target strain HP60 was obtained from fermented soybean by analysis of proteases of the fermentation broth via further screenings. Enzyme activity of HP60 and degree of hydrolysis of RDP were reached(263±7) U/m L and 15.63%±0.30%,respectively. The HP60 was identified as Bacillus amyloliquefaciens by morphological,physiological and biochemical characteristics(API 20 NE,Biolog GP) and 16 S r RNA sequence analysis and collected in China Center for Type Culture Collection(CCTCC),collection number:CCTCC NO. M2014200. In this study,Bacillus amyloliquefaciens HP60 have laied a preliminary foundation for microbial utilization of rice dreg protein.