Desulfotomaculum carboxydivorans sp. nov., a novel sulfate-reducing bacterium capable of growth at 100 % CO

Abstract

A moderately thermophilic, anaerobic, chemolithoheterotrophic, sulfate-reducing bacterium, strain CO-1-SRB T , was isolated from sludge from an anaerobic bioreactor treating paper mill wastewater. Cells were Gram-positive, motile, spore-forming rods. The temperature range for growth was 30-68 6C, with an optimum at 55 6C. The NaCl concentration range for growth was 0-17 g l "1; there was no change in growth rate until the NaCl concentration reached 8 g l . The pH range for growth was 6?0-8?0, with an optimum of 6?8-7?2. The bacterium could grow with 100 % CO in the gas phase. With sulfate, CO was converted to H 2 and CO 2 and part of the H 2 was used for sulfate reduction; without sulfate, CO was completely converted to H 2 and CO 2 . With sulfate, strain CO-1-SRB T utilized H 2 /CO 2 , pyruvate, glucose, fructose, maltose, lactate, serine, alanine, ethanol and glycerol. The strain fermented pyruvate, lactate, glucose and fructose. Yeast extract was necessary for growth. Sulfate, thiosulfate and sulfite were used as electron acceptors, whereas elemental sulfur and nitrate were not. A phylogenetic analysis of 16S rRNA gene sequences placed strain CO-1-SRB T in the genus Desulfotomaculum, closely resembling Desulfotomaculum nigrificans DSM 574 T and Desulfotomaculum sp. RHT-3 (99 and 100 % similarity, respectively). However, the latter strains were completely inhibited above 20 and 50 % CO in the gas phase, respectively, and were unable to ferment CO, lactate or glucose in the absence of sulfate. DNA-DNA hybridization of strain CO-1-SRB T with D. nigrificans and Desulfotomaculum sp. RHT-3 showed 53 and 60 % relatedness, respectively. On the basis of phylogenetic and physiological features, it is suggested that strain CO-1-SRB T represents a novel species within the genus Desulfotomaculum, for which the name Desulfotomaculum carboxydivorans is proposed. This is the first description of a sulfate-reducing micro-organism that is capable of growth under an atmosphere of pure CO with and without sulfate. The type strain is CO-1-SRB T (=DSM 14880 T =VKM B-2319 T ).

A metagenomic window into carbon metabolism at 3 km depth in Precambrian continental crust

“…A carboxydovore-related CODH with 94% nucleotide identity to Desulfotomaculum carboxydivorans CO-1-SRB was identified in the TT107 metagenome (Supplementary Table S6). D. carboxydivorans CO-1-SRB is a bacterium that was cultured in 100% pCO headspace and with the absence of any other electron donors, carbon substrates and sulfate (Parshina et al, 2005). Parshina et al (2005) found that the D. carboxydivorans CO-1-SRB oxidized CO to CO 2 while reducing H 2 O to H 2 and, upon the addition of sulfate, switched to sulfate reduction.…”

“…D. carboxydivorans CO-1-SRB is a bacterium that was cultured in 100% pCO headspace and with the absence of any other electron donors, carbon substrates and sulfate (Parshina et al, 2005). Parshina et al (2005) found that the D. carboxydivorans CO-1-SRB oxidized CO to CO 2 while reducing H 2 O to H 2 and, upon the addition of sulfate, switched to sulfate reduction. In TT107, Desulfotomaculum, is the most Figure 4 The normalized abundances of PEGs within the 'carbon monoxide induced hydrogenase' RAST category are shown.…”

H2 enrichment from synthesis gas by Desulfotomaculumcarboxydivorans for potential applications in synthesis gas purification and biodesulfurization

“…Tests for assessing selected physiological features of D. carboxydivorans (DSM 14880, VKM B-2319;Parshina et al 2005b) were all performed in serum bottles incubated in a temperature-controlled (55°C) shaker type RFI-125 (Infors AG, Basel, Switzerland) at 200 rpm. The basal medium contained (in mM): NaCl 5.1, NH 4 Cl 5.6, CaCl 2 ·2H 2 O 0.7, MgCl 2 ·6H 2 O 0.5, Na 2 S·9H 2 O 0.6, yeast extract 500 mg l −1 , and 1 ml l −1 of an acid-and-alkaline trace element solution according to Stams et al (1993).…”

“…thermosynthrophicum were shown capable of CO utilization at CO levels in the gas phase up to 50 kPa (Parshina et al 2005a). The recently isolated Desulfotomaculum carboxydivorans is the first sulfate reducer that shows uninhibited growth on 180 kPa CO at 55°C, both in the presence and absence of sulfate (Parshina et al 2005b). In the absence of sulfate, it grows hydrogenogenically on CO producing nearly equimolar amounts of H 2 and CO 2 (Parshina et al 2005b).…”

Desulfotomaculum alcoholivorax sp. nov., a moderately thermophilic, spore-forming, sulfate-reducer isolated from a fluidized-bed reactor treating acidic metal- and sulfate-containing wastewater

“…The previously described mesophilic (optimal temperature 25-40 u C) Desulfotomaculum species are D. ruminis (Campbell & Postgate, 1965), D. acetoxidans (Widdel & Pfennig, 1977), D. sapomandens (Cord-Ruwisch & Garcia, 1985), D. aeronauticum (Hagenauer et al, 1997), D. halophilum (Tardy-Jacquenod et al, 1998) and D. gibsoniae (Kuever et al, 1999). The thermophilic (optimal temperature 50-70 u C) species are D. alkaliphilum (Pikuta et al, 2000), D. australicum (Love et al, 1993), D. carboxydivorans (Parshina et al, 2005), D. geothermicum (Daumas et al, 1988), D. kuznetsovii (Nazina et al, 1989), D. luciae (Liu et al, 1997), D. nigrificans (Werkman & Weaver, 1927;Campbell & Postgate, 1965), D. putei (Liu et al, 1997), D. solfataricum (Goorissen et al, 2003), D. thermoacetoxidans (Min & Zinder, 1990), D. thermobenzoicum with two subspecies, namely subsp. thermobenzoicum and subsp.…”