Abstract:The studies were conducted to evaluate crude protein, bioactive peptides, phytic acid and amino acid composition of SBM by solid state fermentation with combined bacteria. According to single bacteria supplemented, four groups were designed to obtain suitable strains for subsequent trials, i.e. unfermented group, Bacillus subtilis group, Saccharomyces cerevisiae and Lactobacillus plantarum group. The results showed that crude protein content of S. cerevisiae group was improved to 50.54%. Based on different volume ratios of B. subtilis to S. cerevisiae, four groups were designed as 1:1(group Ⅰ), 2:1(group Ⅱ), 1:2(group Ⅲ) and unfermented group. Crude protein content was significantly improved after solid fermentation (P<0.05), and increased by 14.09% in group Ⅰ, while no significance was found between three fermentation groups (P>0.05). Compared with unfermented soybean meal, molecular weight of proteins of fermented soybean meal got smaller. With the proportion of B. subtilis increased, the content of small peptide was improved significantly, meanwhile phytic acid decreased remarkably (P<0.05). The content of peptide in group Ⅱ was increased by 678.47% and phytic acid decreased by 38.81%. Free amino acids increased by 256.0% mainly in Ile, Leu and Phe after fermentation. The results indicate that solid state fermentation with B. subtilis as dominant bacteria can improve the nutrient value of soybean meal.