TY - JOUR
T1 - Bile acid oxidation by Eggerthella lenta strains C592 and DSM 2243T
AU - Harris, Spencer C.
AU - Devendran, Saravanan
AU - Méndez- García, Celia
AU - Mythen, Sean M.
AU - Wright, Chris L.
AU - Fields, Christopher J.
AU - Hernandez, Alvaro G.
AU - Cann, Isaac
AU - Hylemon, Phillip B.
AU - Ridlon, Jason M.
N1 - Funding Information:
We gratefully acknowledge the financial support provided to J. M.R. for new faculty startup through the Department of Animal Sciences at the University of Illinois at Urbana-Champaign (Hatch ILLU-538-916) and through the Microbial Metabolic Engineering Theme directed by I.C. P.B.H. is supported through Veterans Affairs Merit Grant BX001328. We thank Dr. Fusae Takamine for providing the bacterial strain C592 from which this work follows.
Funding Information:
Hatch (USDA) (ILLU-538-916) U.S. Department of Veterans Affairs (VA) (BX001328). We gratefully acknowledge the financial support provided to J.M.R. for new faculty startup through the Department of Animal Sciences at the University of Illinois at Urbana-Champaign (Hatch ILLU-538-916) and through the Microbial Metabolic Engineering Theme directed by I.C. P.B.H. is supported through Veterans Affairs Merit Grant BX001328. We thank Dr. Fusae Takamine for providing the bacterial strain C592 from which this work follows.
Publisher Copyright:
© 2018, © 2018 Taylor & Francis.
PY - 2018/11/2
Y1 - 2018/11/2
N2 - Strains of Eggerthella lenta are capable of oxidation-reduction reactions capable of oxidizing and epimerizing bile acid hydroxyl groups. Several genes encoding these enzymes, known as hydroxysteroid dehydrogenases (HSDH) have yet to be identified. It is also uncertain whether the products of E. lenta bile acid metabolism are further metabolized by other members of the gut microbiota. We characterized a novel human fecal isolate identified as E. lenta strain C592. The complete genome of E. lenta strain C592 was sequenced and comparative genomics with the type strain (DSM 2243) revealed high conservation, but some notable differences. E. lenta strain C592 falls into group III, possessing 3α, 3β, 7α, and 12α-hydroxysteroid dehydrogenase (HSDH) activity, as determined by mass spectrometry of thin layer chromatography (TLC) separated metabolites of primary and secondary bile acids. Incubation of E. lenta oxo-bile acid and iso-bile acid metabolites with whole-cells of the high-activity bile acid 7α-dehydroxylating bacterium, Clostridium scindens VPI 12708, resulted in minimal conversion of oxo-derivatives to lithocholic acid (LCA). Further, Iso-chenodeoxycholic acid (iso-CDCA; 3β,7α-dihydroxy-5β-cholan-24-oic acid) was not metabolized by C. scindens. We then located a gene encoding a novel 12α-HSDH in E. lenta DSM 2243, also encoded by strain C592, and the recombinant purified enzyme was characterized and substrate-specificity determined. Genomic analysis revealed genes encoding an Rnf complex (rnfABCDEG), an energy conserving hydrogenase (echABCDEF) complex, as well as what appears to be a complete Wood-Ljungdahl pathway. Our prediction that by changing the gas atmosphere from nitrogen to hydrogen, bile acid oxidation would be inhibited, was confirmed. These results suggest that E. lenta is an important bile acid metabolizing gut microbe and that the gas atmosphere may be an important and overlooked regulator of bile acid metabolism in the gut.
AB - Strains of Eggerthella lenta are capable of oxidation-reduction reactions capable of oxidizing and epimerizing bile acid hydroxyl groups. Several genes encoding these enzymes, known as hydroxysteroid dehydrogenases (HSDH) have yet to be identified. It is also uncertain whether the products of E. lenta bile acid metabolism are further metabolized by other members of the gut microbiota. We characterized a novel human fecal isolate identified as E. lenta strain C592. The complete genome of E. lenta strain C592 was sequenced and comparative genomics with the type strain (DSM 2243) revealed high conservation, but some notable differences. E. lenta strain C592 falls into group III, possessing 3α, 3β, 7α, and 12α-hydroxysteroid dehydrogenase (HSDH) activity, as determined by mass spectrometry of thin layer chromatography (TLC) separated metabolites of primary and secondary bile acids. Incubation of E. lenta oxo-bile acid and iso-bile acid metabolites with whole-cells of the high-activity bile acid 7α-dehydroxylating bacterium, Clostridium scindens VPI 12708, resulted in minimal conversion of oxo-derivatives to lithocholic acid (LCA). Further, Iso-chenodeoxycholic acid (iso-CDCA; 3β,7α-dihydroxy-5β-cholan-24-oic acid) was not metabolized by C. scindens. We then located a gene encoding a novel 12α-HSDH in E. lenta DSM 2243, also encoded by strain C592, and the recombinant purified enzyme was characterized and substrate-specificity determined. Genomic analysis revealed genes encoding an Rnf complex (rnfABCDEG), an energy conserving hydrogenase (echABCDEF) complex, as well as what appears to be a complete Wood-Ljungdahl pathway. Our prediction that by changing the gas atmosphere from nitrogen to hydrogen, bile acid oxidation would be inhibited, was confirmed. These results suggest that E. lenta is an important bile acid metabolizing gut microbe and that the gas atmosphere may be an important and overlooked regulator of bile acid metabolism in the gut.
KW - 7α-dehydroxylation
KW - Eggerthella
KW - Rnf complex
KW - bile acid
KW - hydroxysteroid dehydrogenase
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U2 - 10.1080/19490976.2018.1458180
DO - 10.1080/19490976.2018.1458180
M3 - Article
C2 - 29617190
AN - SCOPUS:85046731594
SN - 1949-0976
VL - 9
SP - 523
EP - 539
JO - Gut Microbes
JF - Gut Microbes
IS - 6
ER -