Syntrophomonas wolfei gen. nov. sp. nov., an Anaerobic, Syntrophic, Fatty Acid-Oxidizing Bacterium

Abstract

An anaerobic, nonphototrophic bacterium that β-oxidizes saturated fatty acids (butyrate through octanoate) to acetate or acetate and propionate using protons as the electron acceptor (H 2 as electron sink product) was isolated in coculture with either a non-fatty acid-degrading, H 2 -utilizing Desulfovibrio sp. or methanogens. Three strains of the bacterium were characterized and are described as a new genus and species, Syntrophomonas wolfei. S. wolfei is a gram-negative, slightly helical rod with round ends that possesses between two to eight flagella laterally inserted along the concave side of the cell. It has a multilayered cell wall of the gram-negative type. The presence of muramic acid, inhibition of growth by penicillin, and increased sensitivity of the cells to lysis after treatment with lysozyme indicate that peptidoglycan is present in the cell wall. Cells of S. wolfei contain poly-β-hydroxybutyrate. Isoheptanoate was degraded to acetate, isovalerate, and H 2 . Carbohydrates, proteinaceous materials, alcohols, or other tested organic compounds do not support growth. Common electron acceptors are not utilized with butyrate as the electron donor. Growth and degradation of fatty acids occur only in syntrophic association with H 2 -using bacteria. The most rapid generation time obtained by cocultures of S. wolfei with Desulfovibrio and Methanospirillum hungatei is 54 and 84 h, respectively. The addition of Casamino Acids but neither Trypticase nor yeast extract stimulated growth and resulted in a slight decrease in the generation time of S. wolfei cocultured with M. hungatei. The addition of H 2 to the medium stopped growth and butyrate degradation by S. wolfei.

Methanogenesis and methanogenic pathways in a peat from subarctic permafrost

“…Because H2 partial pressures were permissive for syntrophic processes (Schink, 1997) (Fig. 1B, Table 1), we propose that butyrate was used syntrophically by an organism like Syntrophomonas wolfei together with methanogens (McInerney et al, 1979;1981) Supporting this, Gibbs free energies were exergonic for reaction (1) at all temperatures including initial and final concentrations (-23.5 kJ per reaction and -30 kJ per reaction, respectively, between 9.2°C and 34.7°C). The overall reaction (4) shows that theoretically 5 mol CH4 are produced from 2 mol butyrate, with 1 mol CH4 coming from H2/CO2 and 4 mol from acetate.…”

Synthesis and function of polyhydroxyalkanoates in anaerobic syntrophic bacteria

“…The analysis of the products made from the various saturated and unsaturated fatty acid substrates suggested that these compounds are metabolized by a /3-oxidation pathway [21]. Enzymatic studies of Wofford et al [26] and McInerney and Wofford [27] confirmed that these compounds were degraded by a/3-oxidation pathway.…”

“…In C. botulinum, PHB is produced before sporulation, and its role is presumably to serve as a carbon/energy reserve for the sporulation process [20]. Interestingly, S. wolfei subspecies wolfei, and S. wolfei subspecies saponavida contain PHA [21][22][23]. We have recently found that a benzoatedegrading syntrophic bacterium morphologically similar to S. buswellii produces PHA when grown in coculture with benzoate, or in pure culture with crotonate as the energy sources (D.A.…”

“…wolfei S. wolfei metabolizes C 4 to C 8 saturated fatty acids to acetate and H 2, or acetate, propionate, and H 2, for even-and odd-numbered fatty acids, respectively [21,25]. Isoheptanoate is degraded to isovalerate, acetate, and H 2.…”

“…Further studies on the physiology of PHA production in syntrophic bacteria are required in order to determine whether PHA plays a role in regulating the thermodynamic efficiency of ATP synthesis. [52] and determining the presence of crotonate in the isolated granule spectrophotometrically [21], and by high-pressure liquid chromatography [23]. About 70% of the colonies picked after electroporation of strain JM109 contained recombinant DNA as indicated by the presence of inserts in purified plasmid DNA.…”