Anaerobic fermentation of soybean meal by Bacillus subtilis ED-3-7 and its effect on the intestinal microbial community of chicken

A strain named ED-3-7 with a high protease-producing ability was screened in a previous study. This strain can be used for the anaerobic fermentation of soybean meal (SBM) to degrade macromolecular antigen proteins and antinutritional factors. We here evaluated the nutritional quality of the anaerobic fermented SBM and its effects on the chicken intestinal microbial community. Crude protein and acid-soluble protein contents increased by 11.68% and 342.61%, glycinin and β-conglycinin decreased by 82.04% and 88.42%, urease content decreased by 90.10%, and the trypsin inhibitor content was lower than the range specified in the detection kit. After being fed with the fermented SBM, the average daily gain, nutrient digestibility of the chickens increased, and their intestinal bacterial community exhibited significant changes. The richness and diversity of bacterial species decreased, and Lactobacillus became the dominant genus, which was conducive to the health of chicken intestines. The experimental results revealed that ED-3-7 anaerobic fermentation improved the nutritional quality of SBM and had beneficial effects on chicken intestines. Thus, the strain could be used for large-scale industrial production.