Energetics of syntrophic fatty acid oxidation

Schink, B

doi:10.1016/0168-6445(94)90105-8

Cited by 20 publications

(26 citation statements)

References 20 publications

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“…Growth of the coculture with crotonate was possible in the presence of bromoethane sulfonate, indicating that crotonate dismutation to acetate and butyrate did not require FIG. 4 (51,60), glycolate (18,46), and benzoate (48), whereas syntrophic degradation of propionate also includes formate as an electron carrier, perhaps simultaneous with hydrogen (13,17). The pathway of substrate degradation was analyzed by enzyme measurements with cell extracts of the coculture.…”

Section: Discussionmentioning

confidence: 99%

Syntrophic Degradation of Cadaverine by a Defined Methanogenic Coculture

Roeder

Schink

2009

Appl Environ Microbiol

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A novel, strictly anaerobic, cadaverine-oxidizing, defined coculture was isolated from an anoxic freshwater sediment sample. The coculture oxidized cadaverine (1,5-diaminopentane) with sulfate as the electron acceptor. The sulfate-reducing partner could be replaced by a hydrogenotrophic methanogenic partner. The defined coculture fermented cadaverine to acetate, butyrate, and glutarate plus sulfide or methane. The key enzymes involved in cadaverine degradation were identified in cell extracts. A pathway of cadaverine fermentation via 5-aminovaleraldehyde and crotonyl-coenzyme A with subsequent dismutation to acetate and butyrate is suggested. Comparative 16S rRNA gene analysis indicated that the fermenting part of the coculture belongs to the subphylum Firmicutes but that this part is distant from any described genus. The closest known relative was Clostridium aminobutyricum, with 95% similarity.Cadaverine is a biogenic primary aliphatic amine. Together with other biogenic amines, like putrescine or spermidine, it is formed during oxygen-limited decomposition of protein-rich organic matter by decarboxylation of amino acids or by amination of aldehydes and ketones (8,27,30,42,53,54). These putrid-smelling and, at higher concentrations (100 to 400 mg per kg), often toxic compounds play a major role in food microbiology, e.g., as flavoring constituents in the ripening of cheese or as contaminants of fish and meat products, wine, and beer (24,29,49).Little is known about the degradation of primary amines. Mono-and diamine oxidases of higher organisms and bacteria (23, 41, 64) initiate aerobic degradation, leading to the respective formation of aldehyde, ammonia, and hydrogen peroxide as products (28). Alternatively, in a putrescine-degrading mutant of Escherichia coli, putrescine is degraded by a putrescine-2-oxoglutarate transaminase and a subsequent dehydrogenase to form 4-aminobutyrate, which is further metabolized via succinate (43).Anaerobic degradation of primary amines could follow basically similar pathways. The released reducing equivalents can be disposed of in a manner similar to that described for primary alcohols (9,15,16). In the absence of external electron acceptors, such as sulfate or nitrate, incomplete oxidation of cadaverine to fatty acids or dicarboxylic acids could be coupled to syntrophic methane production, homoacetogenesis, or reductive synthesis of long-chain fatty acids (1,25,31).In the present study, we describe a new isolate of strictly anaerobic bacteria which oxidizes cadaverine syntrophically with the methanogen Methanospirillum hungatei and forms acetate, butyrate, glutarate, and methane as products. The enzymes involved in the degradation of cadaverine were identified, and a catabolic pathway is proposed. MATERIALS AND METHODSSources of organisms. The coculture LC 13D was isolated from the enrichment culture La Cad, which was originally inoculated with sediment taken from the Lahn river in Marburg, Germany. Methanospirillum hungatei M1h (DSM 13809) was isolated from digested sludge ...

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Section: Discussionmentioning

confidence: 99%

Syntrophic Degradation of Cadaverine by a Defined Methanogenic Coculture

Roeder

Schink

2009

Appl Environ Microbiol

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“…Indications of a different pathway not involving a symmetrical intermediate have been published earlier for a sewage sludge sample (Tholozan et al 1988), but were never substantiated further. Oxidation of propionate through the methylmalonyl CoA pathway involves oxidation steps in succinate dehydrogenase, malate dehydrogenase, and pyruvate:ferredoxin oxidoreductase, of which the first step represents a special problem with respect to its high standard redox potential; release of hy- drogen from this oxidation step requires a hydrogen partial pressure as low as 10 -10 Pa (Schink and Friedrich 1994), which cannot be maintained by methanogenic bacteria . It has been suggested, therefore, that syntrophic propionate oxidation should involve an energy-dependent reversed electron transport step fueled by ATP hydrolysis at the cytoplasmic membrane.…”

Section: Physiology and Biochemistrymentioning

confidence: 99%

Syntrophobacter pfennigii sp. nov., new syntrophically propionate-oxidizing anaerobe growing in pure culture with propionate and sulfate

1995

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A new strain of syntrophically propionate-oxidizing fermenting bacteria, strain KoProp1, was isolated from anoxic sludge of a municipal sewage plant. It oxidized propionate or lactate in cooperation with the hydrogen-and formate-utilizing Methanospirillum hungatei and grew as well in pure culture without a syntrophic partner with propionate or lactate plus sulfate as energy source. In all cases, the substrates were oxidized stoichiometrically to acetate and CO 2 , with concomitant formation of methane or sulfide. Cells formed gas vesicles in the late growth phase and contained cytochromes b and c, a menaquinone-7, and desulforubidin, but no desulfoviridin. Enzyme measurements in cell-free extracts indicated that propionate was oxidized through the methylmalonyl CoA pathway. Protein pattern analysis by SDS-PAGE of cell-free extracts showed that strain KoProp1 differs significantly from Syntrophobacter wolinii and from the propionate-oxidizing sulfate reducer Desulfobulbus propionicus. 16S rRNA sequence analysis revealed a significant resemblance to S. wolinii allowing the assignment of strain KoProp1 to the genus Syntrophobacter as a new species, S. pfennigii. (1) ∆G 0´ = +76.0 kJ/mol propionate The hydrogen partial pressure has to be kept low by the partner organism to make the reaction energetically feasible, e.g., in syntrophic methanogenic propionate degradation: 4 CH 3 CH 2 COO -+ 2 H 2 O→4 CH 3 COO -+ CO 2 +3 CH 4 (2) ∆G 0´ = -26.5 kJ/mol propionate However, the amount of free energy liberated during syntrophic propionate oxidation is still low and just in the range of the minimum energy quantum needed for ATP formation by each partner bacterium (Schink 1990. So far, only one defined syntrophic propionate-degrading culture, Syntrophobacter wolinii, has been described; this culture contains a methanogenic bacterium and a sulfatereducing partner bacterium (Boone and Bryant 1980). It has been shown recently that the propionate-fermenting partner bacterium in this mixed culture could be grown in pure culture, either with pyruvate alone or with propionate plus sulfate as substrates (Wallrabenstein et al. 1994). Another propionate-degrading syntrophic anaerobe, strain MPOB, has been recently obtained in an enrichment culture with propionate plus fumarate as substrates, which were fermented to acetate, CO 2 , and succinate ); a thermophilic methanogenic propionate-oxidizing syntrophic enrichment culture has also been described (Stams et al. 1992). Key wordsThe present study reports on the isolation and characterization of a new strain of syntrophically propionate-oxidizing fermenting bacteria that grows also in pure culture by propionate-dependent sulfate reduction and represents a new species within the genus Syntrophobacter. Christina Wallrabenstein · Elisabeth Hauschild · Bernhard SchinkSyntrophobacter pfennigii sp. nov., new syntrophically propionate-oxidizing anaerobe growing in pure culture with propionate and sulfate Arch Microbiol (1995) 164 : 346-352

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“…1 yields -78 kJ per mol glycolate under standard conditions (calculated according to Thauer et al 1977). This amount of free energy could account for synthesis of one mol ATP per mol glycolate, assuming consumption of 70 kJ mo1-1 for irreversible ATP synthesis in a living cell (Schink 1992). The observed molar growth yield of 4.5 g per mol glycolate is lower than expected, assuming that 10 g cell dry mass is formed per mol ATP (Stouthamer 1979).…”

Section: Energeticsmentioning

confidence: 85%

Isolation and characterization of a desulforubidin-containing sulfate-reducing bacterium growing with glycolate

Friedrich

Schink

1995

Arch. Microbiol.

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Sulfate-dependent degradation of glycolate was studied with a new sulfate-reducing bacterium, strain PerGlyS, enriched and isolated from marine anoxic sediment. Cells were gram-negative, motile rods with a DNA G+C content of 56.2 + 0.2 tool%. Cytochromes of the b-and ctype and menaquinone-5 were detected. A sulfite reductase of the desulforubidin-type was identified by characteristic absorption maxima at 279, 396, 545, and 580 nm. The purified desulforubidin is a heteropolymer consisting of three subunits with molecular masses of 42.5 (o9, 38.5 ([3), and 13 kDa (7). Strain PerGlyS oxidized glycolate completely to CO2. Lactate, malate, and fumarate were oxidized incompletely, yielding more sulfide and less acetate than expected for typical incomplete oxidation of these substrates. Part of the acetate residues formed was oxidized through the CO-dehydrogenase pathway. The biochemistry of glycolate degradation was investigated in cell-free extracts. A membrane-bound glycolate dehydrogenase, but no glyoxylate-metabolizing enzyme activity was detected; the further degradation pathway is unclear.

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Energetics of syntrophic fatty acid oxidation

Cited by 20 publications

References 20 publications

Syntrophic Degradation of Cadaverine by a Defined Methanogenic Coculture

Syntrophic Degradation of Cadaverine by a Defined Methanogenic Coculture

Syntrophobacter pfennigii sp. nov., new syntrophically propionate-oxidizing anaerobe growing in pure culture with propionate and sulfate

Isolation and characterization of a desulforubidin-containing sulfate-reducing bacterium growing with glycolate

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