Isolation of a Highly Efficient Antigenic-Protein-Degrading Bacillus amyloliquefaciens and Assessment of Its Safety
The Key Laboratory of Feed Biotechnology of Ministry of Agriculture, National Engineering Research Center of Biological Feed, Feed Research Institute, Chinese Academy of Agricultural Sciences, No.12 Zhongguancun South Street, Haidian District, Beijing 100081, China
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Received: 22 June 2020 / Revised: 1 July 2020 / Accepted: 3 July 2020 / Published: 6 July 2020
Soybean meal (SBM), a byproduct of soybean oil extraction, is a commonly used dietary protein in the poultry and swine feed industries because of its high quality protein and relatively well-balanced amino acids. However, major antigenic proteins in SBM, glycinin and β-conglycinin, can trigger allergic reactions, including intestine villus atrophy and other malabsorption syndromes, in newborn animals. Microbial fermentation is considered an economically viable processing technique to reduce the content of antigenic proteins, and improve the nutritional quality of SBM. The kind of microorganism used in fermentation is one of the major factors affecting the nutritional value of SBM. In this study, a highly efficient Bacillus. amyloliquefaciens strain was successfully isolated with convenient and effective plate tests, and used in a fermentation experiment. Fermentation with B. amyloliquefaciens for 24 h effectively degraded the glycinin and β-conglycinin in SBM, significantly improved the crude protein content and acid soluble protein concentration, and increased the total amino acid content. Furthermore, B. amyloliquefaciens had no adverse effects on animal health. These results indicate that the B. amyloliquefaciens strain isolated in this study is safe for animal use and can be widely used in SBM fermentation.