Acceleration of Aglycone Isoflavone and γ-Aminobutyric Acid Production from Doenjang Using Whole-Cell Biocatalysis Accompanied by Protease Treatment

• Published in: Journal of microbiology and biotechnology Vol. 27; no. 11; pp. 1952 - 1960
• Main Authors: Li, Yincong, Ku, Seockmo, Park, Myeong Soo, Li, Zhipeng, Ji, Geun Eog
• Format: Journal Article
• Language: English
• Published: Korea (South) 한국미생물·생명공학회 01.11.2017
• Subjects: Aspergillus oryzae - metabolism; Biocatalysis; Bioreactors; Endopeptidases - metabolism; Fermentation; gamma-Aminobutyric Acid - biosynthesis; Genistein; Glycine max - metabolism; Glycosides; Isoflavones - biosynthesis; Levilactobacillus brevis - metabolism; Probiotics; 생물학; Whole-cell catalysis; bioconversion; doenjang; γ-aminobutyric acid; probiotics; soybean isoflavone
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1705.05052

Recently, soybean isoflavone aglycones ( , daidzein and genistein) and γ-aminobutyric acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides ( , daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. GABA 100 and KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and 59 μg/g, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell GABA 100 and KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.