Abstract
An anaerobic incubation mixture of two bacterial strains Eggerthella sp. Julong 732 and Lactobacillus sp. Niu-O16, which have been known to transform dihydrodaidzein to S-equol and daidzein to dihydrodaidzein respectively, produced S-equol from daidzein through dihydrodaidzein. The biotransformation kinetics of daidzein by the mixed cultures showed that the production of S-equol from daidzein was significantly enhanced, as compared to the production of S-equol from dihydrodaidzein by Eggerthella sp. Julong 732 alone. The substrate daidzein in the mixed culture was almost completely converted to S-equol in 24 h of anaerobic incubation. The increased production of S-equol from daidzein by the mixed culture is likely related to the increased bacterial numbers of Eggerthella sp. Julong 732. In the mixture cultures, the growth of Eggerthella sp. Julong 732 was significantly increased while the growth of Lactobacillus sp. Niu-O16 was suppressed as compared to either the single culture of Eggerthella sp. Julong 732 or Lactobacillus sp. Niu-O16. This is the first report in which two metabolic pathways to produce S-equol from daidzein by a mixed culture of bacteria isolated from human and bovine intestinal environments were successfully linked under anaerobic conditions.
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We thank Dr. R. A. Kanaly at Kyoto University, Japan, for editorial comments. This work was supported by Korea Research Foundation Grant KRF-2004–041-F00014, Korea and by a grant from the MOST/KOSEF to the Environmental Biotechnology National Core Research Center (grant #: R15-2003-012-02002-0), Korea.
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Wang, XL., Kim, HJ., Kang, SI. et al. Production of phytoestrogen S-equol from daidzein in mixed culture of two anaerobic bacteria. Arch Microbiol 187, 155–160 (2007). https://doi.org/10.1007/s00203-006-0183-8
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DOI: https://doi.org/10.1007/s00203-006-0183-8