image:
Supersulfide content was assessed in dried and fermented soybeans to analyze changes before and during fermentation using Bacillus subtilis var. natto.
view more
Credit: Osaka Metropolitan University
Supersulfide molecules, metabolites from plants that are important in cellular metabolism, are attracting attention in the medical and nutritional fields for their potential in supporting health and disease prevention. Natto, a Japanese food made from soybeans fermented with the Bacillus subtilis var. natto microorganism, is rich in these molecules. However, the mechanism by which they are produced during fermentation has remained unclear.
To better understand this complex process, a research group led by Professor Hideshi Ihara at Osaka Metropolitan University’s Graduate School of Science extensively analyzed supersulfide content in natto fermentation using various methods. The researchers first compared supersulfides in dried soybeans from three different suppliers and four commercial natto brands. The supersulfides in the soybean variants did not have significant differences. Comparatively, the natto samples showed higher supersulfide content and varying levels between brands. The team then observed supersulfides during the fermentation process using Bacillus subtilis var. natto in homemade natto from two dried bean samples.
Results revealed an increase in soybean supersulfides, indicating that natto bacteria actively convert other sulfur molecules into supersulfide molecules by breaking down soybean proteins and other substances. Further, it was found that soybeans that underwent heat treatment had an increase in supersulfides before fermentation.
“This achievement is the world’s first demonstration that microbial fermentation dramatically alters the supersulfide molecule profile of plants,” said Professor Ihara, “Advances in understanding the mechanisms behind natto’s health benefits could contribute to maintaining and improving people’s health, such as reducing the risk of cardiovascular disease.”
The study was published in Nitric Oxide.
###
About OMU
Established in Osaka as one of the largest public universities in Japan, Osaka Metropolitan University is committed to shaping the future of society through the “Convergence of Knowledge” and the promotion of world-class research. For more research news, visit https://www.omu.ac.jp/en/ and follow us on social media: X, Facebook, Instagram, LinkedIn.
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Dynamic Transformation of the Sulfur Metabolome during Natto Fermentation: Supersulfide Omics Study
Article Publication Date
4-Nov-2025
COI Statement
The authors declare that there are no conflicts of interest.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
AloJapan.com