What You Need to Know
During fermentation, Bacillus subtilis var. natto metabolizes soybean proteins and carbohydrates, secreting enzymes such as nattokinase and producing poly‑γ‑glutamic acid. The polymer forms a sticky, water‑binding matrix while the bacterium’s proteolytic activity generates peptides that contribute to the characteristic umami flavor. The process also lowers the pH to ~6.3, optimizing microbial growth and enzyme stability.
The Science
Primary Reaction
Fermentation of soybean substrates by Bacillus subtilis var. natto producing poly‑γ‑glutamic acid and nattokinase