Sporomusa silvacetica sp. nov., an Acetogenic Bacterium Isolated from Aggregated Forest Soil

Abstract

Sporomusa silvacetica sp. nov. DG-lT (= DSMZ 10669T) (T = type strain) was isolated from well-drained, aggregated forest soil (pH 6.0) in east-central Germany. The cells were obligately anaerobic, slightly curved rods and were motile by means of laterally inserted flagella on the concave side of each cell. Typical cells were approximately 3.5 by 0.7 pm. Cells stained weakly gram positive, but thin sections revealed a complex multilayer cell wall. Spores were spherical and distended the sporangia. Growth and substrate utilization occurred with ferulate, vanillate, fructose, betaine, fumarate, 2,3-butanediol, pyruvate, lactate, glycerol, ethanol, methanol, formate, and H,-CO,. With most substrates, acetate was the primary reduced end product and was produced in stoichiometries indicative of an acetyl-coenzyme A pathway-dependent metabolism. Fumarate was dismutated to succinate and acetate. Methoxyl and acrylate groups of various aromatic compounds were 0-demethylated and reduced, respectively. Yeast extract was not required for growth. Cells grew optimally at approximately 30°C and pH 6.8; under these conditions and with fructose as the substrate, the doubling time was approximately 14 h. The lowest temperature that supported growth was between 5 and 10°C. The carbon monoxide dehydrogenase and hydrogenase activities were approximately 9 and 102 pmol min-' mg of protein-', respectively. A type b cytochrome was detected in the membrane. The G+C content was approximately 43 mol%. Phylogenetic analysis of the 16s ribosomal DNA indicated that DG-lT was most closely related to members of the genus Sporomusa in the Clostridium subphylum of the gram-positive bacteria.Low-molecular-weight aliphatic organic acids are present in mineral forest soil solutions and are believed to play roles in soil formation, solubility of toxic metals, and plant growth (23,24,30,49,58,59). In this regard, acetate is a dominate organic acid detected in mineral soils (59), and it has been proposed that the acetate in mineral soils is produced primarily through the collective action of facultatively and obligately anaerobic microorganisms (35,63). Although well-drained soils are not considered typical acetogenic habitats, supplementation of forest (34, 35), prairie (63), and tundra (46) soils with H, or CO results in the utilization of substrates and the production of acetate in stoichiometries approximating those expected for H,-or CO-dependent acetogenesis. In addition, acetogenic consortia are readily enriched from mineral forest soils (35,48) and leaf litter (36). To further evaluate the occurrence of acetogens in well-drained, aggregated soils, an acetogen was isolated from a beech forest in east-central Germany. The collective characteristics of this isolate (strain DG-lT [T = type strain]) are not consistent with the characteristics of any previously described acetogenic bacterium, and it is proposed that this organism should be placed in a new species, Sporomusa silvacetica. MATERIALS AND METHODSSoil collection. Forest soil (a silty loam...

A Complete Sequence of the T. tengcongensis Genome

“…This pathway, catalyzed by enzymes of carbon monoxide dehydrogenase (CODH), formyltetrahydrofolate synthetase, and acetylCoA synthetase, synthesizes acetyl CoA from two molecules of CO 2 (Ragsdale 1991;Kuhner et al 1997). The key enzymes for the acetyl-CoA pathway, such as a CODH subunit CooS (TTE1708) and a formyltetrahydrofolate synthetase (TTE2391), are identified in T. tengcongensis.…”

Anaerospora hongkongensis Gen. Nov. Sp. Nov., a Novel Genus and Species with Ribosomal DNA Operon Heterogeneity Isolated from an Intravenous Drug Abuser with Pseudobacteremia

“…Using this new standard, phylogenetic trees, based on base differences between species, are constructed; and bacteria are classified and re-classified into new genera. Recently, the use of this technique for the identification of bacterial strains with ambiguous biochemical profiles and the discovery of novel genera and species have been reported by us and other researchers (5-7, 10, 16, 18-30).Based on the results of 16S rDNA sequencing, major changes in the taxonomy of anaerobic Gram-negative bacteria have been made in recent years (2,4,9,11,15). At the moment, about 50 genera of anaerobic Gram-negative bacteria have been described, three of which were sporulated.…”

“…Based on the results of 16S rDNA sequencing, major changes in the taxonomy of anaerobic Gram-negative bacteria have been made in recent years (2,4,9,11,15). At the moment, about 50 genera of anaerobic Gram-negative bacteria have been described, three of which were sporulated.…”

Sporomusa intestinalis sp. nov., a homoacetogenic bacterium isolated from the gut of a higher termite, Termes comis (Termitinae)

“…T (Möller et al, 1984); 5, S. sphaeroides strain E T (Möller et al, 1984); 6, S. acidovorans strain Mol T (Ollivier et al, 1985); 7, S. paucivorans strain X T (Hermann et al, 1987); 8, S. malonica strain WoGl2 T (Dehning et al, 1989); 9, S. silvacetica strain DG-1 T (Kuhner et al, 1997); 10, S. rhizae strain RS T (Gößner et al, 2006). +, positive; , negative; w, weakly positive; ND, not determined.…”