Bacillus natto is a type of Bacillus subtilis that lives in dead grass (dead body).When soybeans, which are the raw material of natto, are steamed, they lose their germination ability and become dead bodies. There are many unclear points about the action on the fungus.In this study, live soybeans showing germination ability and dead soybeans that lost germination ability were inoculated with Bacillus natto, and the interaction between the two was investigated at the molecular level.

　As a result, the growth of Bacillus natto was remarkably suppressed in live soybeans, but Bacillus natto grew well in dead soybeans, and the secretion of sticky (sticky) components was confirmed, soybeans changed to natto.Live soybeans also suppressed the growth of Bacillus subtilis.This suggests that live soybeans secrete antibacterial substances that suppress the growth of Bacillus natto and Bacillus subtilis.On the other hand, it was found that Bacillus natto senses the cell wall component of dead (steamed) soybean and proliferates using it as a nutrient source.

　According to this study, living plants suppress the growth of certain bacteria, but when they become dead bodies, they are decomposed by the bacteria. Part of the molecular mechanism involved has been clarified.

　The presence of bacteria such as Bacillus subtilis has been pointed out as the cause of foot odor.In the future, it is expected that antibacterial substances will be isolated and identified from soybeans and applied to drugs.On the other hand, by pursuing the physiological action of natto bacteria on steamed soybeans, he hopes to lead to the production of high-quality natto.

Paper information:[Scientific Reports] Bacterial inducible expression of plant cell wall-binding protein YesO through conflict between Glycine max and saprophytic Bacillus subtilis