title: Does the intestinal microflora synthesize pyrroloquinoline quinone?
abstract: Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, such as methanol dehydrogenase and glucose dehydrogenase. When chemically-defined diets without PQQ are fed to animals, lathyritic changes are observed. In previous studies, it was assumed that PQQ was produced by the intestinal microflora; consequently, antibiotics were routinely added to diets. In the present study this assumption is tested further in mice by: (i) examining the effects of dietary antibiotics on fecal PQQ excretion, (ii) isolating the intestinal flora to identify bacteria known to synthesize PQQ and (iii) determining in vitro if the intestinal microflora synthesizes PQQ from radio-chemically labeled precursors. The results of these experiments indicate that little if any PQQ is synthesized by the intestinal microflora. Rather, when PQQ is present in the intestine, the diet is a more obvious source.
authors.affiliation: Department of Nutrition, University of California, Davis 95616.
authors.forename: C R
authors.initials: CR
authors.lastname: Smidt
authors.forename: D
authors.initials: D
authors.lastname: Bean-Knudsen
authors.forename: D G
authors.initials: DG
authors.lastname: Kirsch
authors.forename: R B
authors.initials: RB
authors.lastname: Rucker
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002852:Chromatography, Ion Exchange; D003067:Coenzymes / Q000378:metabolism*; D005243:Feces / Q000737:chemistry; D007422:Intestines / Q000382:microbiology*; D008297:Male; D051379:Mice; D045542:PQQ Cofactor; D011549:Pseudomonas / Q000378:metabolism; D015363:Quinolones / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D003067:Coenzymes; D015363:Quinolones; D045542:PQQ Cofactor