Work

Screening and Characterization of Marine Bacillus atrophaeus G4 Protease and Its Application in the Enzymatic Hydrolysis of Sheep (Ovis aries) Placenta for the Preparation of Antioxidant Peptides

Year: 2025

Type: article

Abstract: Proteolytic enzymes, which play a crucial role in peptide bond cleavage, are widely applied in various industries. In this study, protease-producing bacteria were isolated and characterized from marine sediments collected from the Yellow Sea, China. Comprehensive screening and 16S rDNA sequencing identified a promising G4 strain as Bacillus atrophaeus. Following meticulous optimization of fermentation conditions and medium composition via response surface methodology, protease production using strain G4 was significantly enhanced by 64%, achieving a yield of 3258 U/mL. The G4 protease exhibited optimal activity at 50 °C and pH 7.5, demonstrating moderate thermal stability with 52% residual activity after 30-min incubation at 50 °C—characteristics typical of an alkaline protease. Notably, the enzyme retained over 79% activity across a broad pH range (6–11) and exhibited excellent salt tolerance, maintaining over 50% activity in a saturated NaCl solution. Inhibition by phenylmethylsulfonyl fluoride, a serine protease inhibitor, confirmed its classification as a serine protease. The enzyme’s potential in generating bioactive peptides was further demonstrated through hydrolysis of sheep (Ovis aries) placenta, resulting in a hydrolysate with notable antioxidant properties. The hydrolysate exhibited a 64% superoxide anion scavenging activity, surpassing that of reduced glutathione. These findings expand the current understanding of Bacillus atrophaeus G4 proteases and provide a foundation for innovative sheep placenta utilization with potential industrial applications.

Source: Molecules

DOI: 10.3390/molecules30102217

Authors: Wei Wang, Guoqing Peng, Jingjing Sun, Chengcheng Jiang, Jianhua Hao, Xiu Zhang

Institutions: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, North Minzu University

Language: English

Topic: Enzyme Production and Characterization

Subfield: Biotechnology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,258

Funder: Central Public-interest Scientific Institution Basal Research Fund, Chinese Academy of Fishery Sciences