ALDEHYDE DEHYDROGENASE-ACTIVITY AND ACETATE PRODUCTION BY AEROBIC-BACTERIA REPRESENTING THE NORMAL FLORA OF HUMAN LARGE-INTESTINE

Citation
T. Nosova et al., ALDEHYDE DEHYDROGENASE-ACTIVITY AND ACETATE PRODUCTION BY AEROBIC-BACTERIA REPRESENTING THE NORMAL FLORA OF HUMAN LARGE-INTESTINE, Alcohol and alcoholism, 31(6), 1996, pp. 555-564
Citations number
48
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Substance Abuse
Journal title
ISSN journal
0735-0414
Volume
31
Issue
6
Year of publication
1996
Pages
555 - 564
Database
ISI
SICI code
0735-0414(1996)31:6<555:ADAAPB>2.0.ZU;2-V
Abstract
We have recently proposed the existence of a bacteriocolonic pathway f or ethanol oxidation, i.e. ethanol is oxidized by alcohol dehydrogenas e of intestinal bacteria resulting in high intracolonic levels of reac tive and toxic acetaldehyde. This study was aimed to examine aldehyde dehydrogenase (ALDH) activity, acetaldehyde consumption and production of acetate by aerobic bacteria (n = 27), representing the normal huma n colonic flora. Most bacterial strains did not show any membrane-asso ciated aldehyde dehydrogenase, but possessed marked cytosolic NADP(+)- and NAD(+)-dependent aldehyde dehydrogenase activity, ranging from 15 5 nmol of NAD(P)H produced/min/mg of protein to zero with acetaldehyde as substrate. NADP(+)-linked ALDH activity was significantly higher t han NAD(+)-linked activity in most of the tested bacteria. In addition , aerobic bacteria metabolized acetaldehyde effectively in vitro and t his could be inhibited by cyanamide in nearly half of the tested strai ns. Production of acetate from acetaldehyde ranged From 2420 nmol/10(9 ) colony-forming units to almost negligible. In conclusion, many human aerobic colonic bacteria possess significant aldehyde dehydrogenase a ctivity and can, consequently, produce acetate from acetaldehyde in vi tro at least under the partially aerobic conditions proposed to prevai l on the colonic mucosal surface. Individual variation in the capabili ty of colonic flora to remove toxic acetaldehyde may be one factor reg ulating intracolonic acetaldehyde levels, as well as the rate of bacte riocolonic pathway for ethanol oxidation.