With triethanolamine as sole source of energy and organic carbon, a strictly anaerobic, gram-positive, rod-shaped bacterium, strain LuTria 3, was isolated from sewage sludge and was assigned to the genus Acetobacterium on the basis of morphological and physiological properties. The G + C content of the DNA was 34.9 + 1.0 mol %. The new isolate fermented triethanolamine to acetate and ammonia. In cell-free extracts, a triethanolaminedegrading enzyme activity was detected that formed acetaldehyde as reaction product. Triethanolamine cleavage was stimulated 30-fold by added adenosylcobalamin (coenzyme B12) and inhibited by cyanocobalamin or hydroxocobalamin. Ethanolamine ammonia lyase, acetaldehyde:acceptor oxidoreductase, phosphate acetyltransferase, acetate kinase, and carbon monoxide dehydrogenase were measured in cell-free extracts of this strain. Our results establish that triethanolamine is degraded by a corrinoid-dependent shifting of the terminal hydroxyl group to the subterminal carbon atom, analogous to a diol dehydratase reaction, to form an unstable intermediate that releases acetaldehyde. No anaerobic degradation of triethylamine was observed in similar enrichment assays.

Strictly anaerobic bacteria were enriched and isolated from freshwater sediment sources in the presence and absence of sulfate with sorbic acid as sole source of carbon and energy. Strain WoSol, a Gram-negative vibrioid sulfate-reducing bacterium which was assigned to the species Desulfoarculus (formerly Desulfovibrio) baarsii oxidized sorbic acid completely to CO2 with concomitant stoichiometric reduction of sulfate to sulfide. This strain also oxidized a wide variety of fatty acids and other organic compounds. A Gram-negative rod-shaped fermenting bacterium, strain AmSol, fermented sorbic acid stoichiometrically to about equal amounts of acetate and butyrate. At concentrations higher than 10 mM, sorbic acid fermentation led to the production of pentanone-2 and isopentanone-2 (3-methyl-2-butanone) as byproducts. Strain AmSol fermented also crotonate and 3-hydroxybutyrate to acetate and butyrate, and hexoses to acetate, ethanol, hydrogen, and formate. The guanine-plus-cytosine content of the DNA was 41.8 + 1.0 mol%. Sorbic acid at concentrations higher than 5 mM inhibited growth of this strain while strain WoSol tolerated sorbic acid up to 10 mM concentration.

With triethanolamine as sole source of energy and organic carbon, a strictly anaerobic, gram-positive, rod-shaped bacterium, strain LuTria 3, was isolated from sewage sludge and was assigned to the genus Acetobacterium on the basis of morphological and physiological properties. The G + C content of the DNA was 34.9 + 1.0 mol %. The new isolate fermented triethanolamine to acetate and ammonia. In cell-free extracts, a triethanolaminedegrading enzyme activity was detected that formed acetaldehyde as reaction product. Triethanolamine cleavage was stimulated 30-fold by added adenosylcobalamin (coenzyme B12) and inhibited by cyanocobalamin or hydroxocobalamin. Ethanolamine ammonia lyase, acetaldehyde:acceptor oxidoreductase, phosphate acetyltransferase, acetate kinase, and carbon monoxide dehydrogenase were measured in cell-free extracts of this strain. Our results establish that triethanolamine is degraded by a corrinoid-dependent shifting of the terminal hydroxyl group to the subterminal carbon atom, analogous to a diol dehydratase reaction, to form an unstable intermediate that releases acetaldehyde. No anaerobic degradation of triethylamine was observed in similar enrichment assays.