Isolation and characterization of two new homoacetogenic hydrogen-utilizing bacteria from the human intestinal tract that are closely related to Clostridium coccoides

• DOI: 10.1128/aem.63.5.1732-1738.1997
• Publication Date: 2020-01-06T18:28:01Z
• Authors: B Kamlage; B Gruhl; M Blaut
• Keywords: Acetogenesis; Human feces

Two gram-positive, strictly anoxic, coccoid- to rod-shaped strains of bacteria, Clostridium coccoides 1410 and C. 3110, were isolated from human feces on the typical homoacetogenic substrates formate plus H2 CO2 (strain 1410) vanillate 3110) in presence 2-bromoethanesulfonate inhibit methanogenesis. On basis 16S rRNA sequencing, DNA-DNA hybridization, physiological morphological parameters, both isolates are closely related DSM 935T. The G+C contents DNA 46.1 46.2 mol% for respectively. Cytochromes could not be detected. Formate was degraded exclusively acetate, whereas O-demethylated, resulting acetate 3,4-dihydroxybenzoate, latter being further decarboxylated catechol. In organic substrates, cometabolized but failed grow autotrophically. Lactose, lactulose, sorbitol, glucose, various other carbohydrates supported growth as well. Untypical homoacetogens, glucose sorbitol fermented acetate; instead, considerable amounts succinate D-lactate produced. evolved only negligible traces. Acetogenesis or constitutive, utilization inducible. Hydrogenase, CO dehydrogenase, all tetrahydrofolic acid-dependent, C1 compound-converting enzymes acetyl-coenzyme A pathway homoacetogenesis present cell extracts.