Effect of Bacillus subtilis and Lactobacillus plantarum on solid-state fermentation of soybean meal.

Background: As feeding probiotics, Bacillus subtilis FJAT-4842 and Lactobacillus plantarum FJAT-13737 were employed to improve the nutritional value and reduce the risk of contamination in the solid-state fermentation of soybean meal (SBM).

Results: After fermentation with bacterium starters, the crude protein, free amino acid and lactic acid increased, with higher protease and cellulose activity. The addition of L. plantarum could increase the crude protein and lactic acid content by 50.1% and 94.9%, respectively. After fermentation, the contents of crude fiber and phytic acid decreased by 45.9% and 48.1%. Compared with control treatment, the addition of both B. subtilis FJAT-4842 and L. plantarum FJAT-13737 could effectively elevate the production of free amino acid and esters. Moreover, the addition of bacterium starter could prevent the production of mycotoxin and promote bacterial diversity of the fermented SBM. Especially, the addition of B. subtilis could reduce the relative content of Staphylococcus. After fermentation for 7 days, lactic acid bacteria including Pediococcus, Weissella and Lactobacillus became the main bacteria in the fermented SBM.

Conclusion: The addition of bacterium starter is of benefit with respect to improving the nutritional value and reducing the risk of contamination in the solid-state fermentation of soybean. © 2023 Society of Chemical Industry.