Microbial Transformation of Bioactive Compounds and Production of ortho-Dihydroxyisoflavones and Glycitein from Natural Fermented Soybean Paste

• Main Author: Changhyun Roh
• Format: Article
• Language: English
• Published: MDPI AG 2014-12-01
• Series: Biomolecules
• Subjects: screening; biotransformation; soybean paste; bioactive compound
• Online Access: http://www.mdpi.com/2218-273X/4/4/1093

Recently, there has been a great deal of remarkable interest in finding bioactive compounds from nutritional foods to replace synthetic compounds. In particular, ortho-dihydroxyisoflavones and glycitein are of growing scientific interest owing to their attractive biological properties. In this study, 7,8-ortho-dihydroxyisoflavone, 6,7-ortho-dihydroxyisoflavone, 3',4'-ortho-dihydroxyisoflavone and 7,4'-dihydroxy-6-methoxyisoflavone were characterized using microorganism screened from soybean Doenjang. Three ortho-dihydroxyisoflavones and glycitein were structurally elucidated by 1H-NMR and GC-MS analysis. Furthermore, bacterial strains from soybean Doenjang with the capacity of biotransformation were screened. The bacterial strain, identified as Bacillus subtilis Roh-1, was shown to convert daidzein into ortho-dihydroxyisoflavones and glycitein. Thus, this study has, for the first time, demonstrated that a bacterial strain had a substrate specificity for multiple modifications of the bioactive compounds.