Anaerobic degradation of flavonoids by Clostridium orbiscindens.
An anaerobic, quercetin-degrading bacterium was isolated from human feces and identified as Clostridium orbiscindens by comparative 16S rRNA gene sequence analysis. The organism was tested for its ability to transform several flavonoids. The isolated C. orbiscindens strain converted quercetin and taxifolin to 3,4-dihydroxyphenylacetic acid; luteolin and eriodictyol to 3-(3,4-dihydroxyphenyl)propionic acid; and apigenin, naringenin, and phloretin to 3-(4-hydroxyphenyl)propionic acid, respectively. Genistein and daidzein were not utilized. The glycosidic bonds of luteolin-3-glucoside, luteolin-5-glucoside, naringenin-7-neohesperidoside (naringin), quercetin-3-glucoside, quercetin-3-rutinoside (rutin), and phloretin-2'-glucoside were not cleaved. Based on the intermediates and products detected, pathways for the degradation of the flavonol quercetin and the flavones apigenin and luteolin are proposed. To investigate the numerical importance of C. orbiscindens in the human intestinal tract, a species-specific oligonucleotide probe was designed and tested for its specificity. Application of the probe to fecal samples from 10 human subjects proved the presence of C. orbiscindens in 8 out of the 10 samples tested. The numbers ranged from 1.87 x 10(8) to 2.50 x 10(9) cells g of fecal dry mass(-1), corresponding to a mean count of 4.40 x 10(8) cells g of dry feces(-1).
Schoefer
Lilian
L
Abteilung Gastrointestinale Mikrobiologie, Deutsches Institut für Ernährungsforschung, 14558 Bergholz-Rehbrücke, Germany.
Mohan
Ruchika
R
Schwiertz
Andreas
A
Braune
Annett
A
Blaut
Michael
M
D000328:Adult; D000693:Anaerobiosis; D047310:Apigenin; D001673:Biodegradation, Environmental; D003013:Clostridium / Q000145:classification / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D003470:Culture Media; D005243:Feces / Q000382:microbiology*; D005419:Flavonoids / Q000378:metabolism*; D006801:Humans; D047311:Luteolin; D008297:Male; D011794:Quercetin / Q000031:analogs & derivatives* / Q000378:metabolism
D003470:Culture Media; D005419:Flavonoids; C012526:quercitrin; D047310:Apigenin; D011794:Quercetin; D047311:Luteolin