title: Deglycosylation of isoflavones in isoflavone-rich soy germ flour by Aspergillus oryzae KACC 40247.
abstract: Aspergillus oryzae KACC 40247 was selected as an efficient daidzein-producing fungus from strains of the genus Aspergillus by using 5% (w/v) soy germ flour (SGF) as an isoflavone-glycoside-rich medium. The culture conditions, including SGF concentration, agitation speed, initial pH, temperature, and time, were optimized as follows: 7% (w/v) SGF, initial pH 6.0, 33 °C, 300 rpm, and 24 h in a 100 mL baffled flask. The determined amount of isoflavone aglycons in SGF using 50% ethyl acetate was the highest among the solvent systems tested and it was 3.7-fold higher than that using 70% methanol. Under the optimized conditions, the content and concentration of daidzein were 134 mg/g of SGF and 9.4 g/L, respectively, with a productivity of 391 ± 2.8 mg/L/h, and those of isoflavone aglycons were 165 mg/g of SGF and 11.5 g/L, respectively, with a productivity of 479 mg/L/h. Optimization of culture conditions increased the content, concentration, and productivity of isoflavone aglycons by 3.1-, 3.0-, and 3.7-fold, respectively. To our knowledge, this is the highest production of isoflavone aglycons reported to date.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University , Seoul 143-701, Republic of Korea.
authors.forename: Seon-Hwa
authors.initials: SH
authors.lastname: Lee
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Seo
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D001236:Aspergillus oryzae / Q000378:metabolism*; D003470:Culture Media / Q000032:analysis / Q000378:metabolism; D005285:Fermentation; D005433:Flour / Q000032:analysis* / Q000382:microbiology; D006031:Glycosylation; D007529:Isoflavones / Q000096:biosynthesis*; D013025:Glycine max / Q000737:chemistry* / Q000382:microbiology; D013696:Temperature
chemical_list: D003470:Culture Media; D007529:Isoflavones; C004742:daidzein