Desulfosporosinus youngiae sp. nov., a spore-forming, sulfate-reducing bacterium isolated from a constructed wetland treating acid mine drainage

Abstract

Strain JW/YJL-B18 T , a spore-forming, sulfate-reducing bacterium, was isolated from constructed wetland sediment. Cells were curved rods, 0.7-1.2 mm in diameter and 3-7 mm long. Despite being phylogenetically a member of the Gram-type-positive phylum Firmicutes, cells stained Gram-negative at all growth phases. Strain JW/YJL-B18 T grew at 8-39 6C, with an optimum at 32-35 6C and no growth at 4 6C or below or at 42 6C or above. The pH 25 6C range for growth was 5.7-8.2, with an optimum at pH 25 6C 7.0-7.3, and no growth was detected at or below pH 5.2 or at or above pH 8.4. The salinity range for growth was 0-3 % (NaCl/KCl 9 : 1). Strain JW/YJL-B18 T utilized as carbon and energy sources beef extract, yeast extract, formate, succinate, lactate, pyruvate, ethanol and toluene. Fumarate, sulfate, sulfite and thiosulfate were reduced in the presence of lactate. Arsenate (V) was not used as an electron acceptor. Strain JW/YJL-B18 T showed no indication of growth under autotrophic conditions. The predominant cellular fatty acids were C 16 : 1 and C 16 : 0 . The genomic DNA G+C content was 36.6 mol% (HPLC). 16S rRNA gene sequence analysis indicated that strain JW/YJL-B18 T fell into the genus Desulfosporosinus, with Desulfosporosinus auripigmenti OREX-4 T as its closest neighbour with a validly published name (97.9 % similarity). Based on molecular genetic evidence and physiological and biochemical characters including differences in the DNA G+C content, we propose to place strain JW/YJL-B18 T (5DSM 17734 T 5ATCC BAA-1261 T ) as the type strain of a novel species, Desulfosporosinus youngiae sp. nov.Sulfate-reducing bacteria (SRB) are responsible for a variety of biogeochemical processes. For example, SRB reduce sulfate to dissolved sulfide (S 22 ), which may react with metals to form metal sulfides; thus, they are considered to play a major role in metal removal and alkalinity generation in treating acid mine drainage. The SRB are an ecologically and metabolically diverse group of anaerobes which include members of the phylum Firmicutes (formerly the phylogenetically Gram-type-positive bacteria; Wiegel, 1981) residing within the family Peptococcaceae in the order Clostridiales. Among them, the genus Desulfosporosinus currently consists of five species of obligately anaerobic, spore-forming bacteria (http:// www.bacterio.cict.fr/d/desulfosporosinus.html). Stackebrandt et al. (1997) distinguished this group from the genus Desulfotomaculum on the basis of phylogenetic evidence and their ability to grow under autotrophic conditions. However, the property of autotrophic growth (i.e. 50 % of the biomass is derived from inorganic carbon) has not been demonstrated unequivocally for all species. Vatsurina et al. (2008) recently reported Desulfosporosinus orientis 343 as the type strain of a novel species in the same genus, Desulfosporosinus hippei, which does not oxidize H 2 with CO 2 or acetate. Here, we report another novel Desulfosporosinus species that is not capable of growing lithotrophically, isolated from a construc...

Microbial communities in the subglacial waters of the Vatnajökull ice cap, Iceland

“…Further, that the relative of Sulfuricurvum kujiense oxidizes sulfide, elemental sulfur (S 0 ) and thiosulfate (S 2 O 3 ) at low oxygen concentrations (Kodama and Watanabe, 2004). We propose that the Desulfosporosinus member uses H 2 to reduce sulfate, thiosulfate or sulfite (SO 3 À ), to elemental sulfur (Ramamoorthy et al, 2006;Vatsurina et al, 2008;Lee et al, 2009;Alazard et al, 2010;Abicht et al, 2011), whereas the Sulfurospirillum member completes the sulfur cycle, reducing elemental sulfur, thiosulfate and sulfite, to sulfide (Finster et al, 1997;Stolz et al, 1999;Jensen and Finster, 2005;Kodama et al, 2007).…”

Bacterial glycerol oxidation coupled to sulfate reduction at neutral and acidic pH

“…From mine streams and lakes with a low pH, sulfatereducing bacteria have been isolated, which could not grow below pH 5 (Küsel et al, 2001;Lee et al, 2009). Pure cultures obtained from mixed cultures capable of reduc- ing sulfate at pH 3 were not able to reduce sulfate below pH 5.5 (Gyure et al, 1990).…”

Complete Genome Sequences of Desulfosporosinus orientis DSM765T, Desulfosporosinus youngiae DSM17734T, Desulfosporosinus meridiei DSM13257T, and Desulfosporosinus acidiphilus DSM22704T

“…They can utilize a wide spectrum of energy sources, ranging from aromatic compounds to short-chained fatty acids. A characteristic feature of many Desulfosporosinus species, distinguishing them from their closest sulfate-reducing relatives of the genus Desulfotomaculum, is their ability to grow chemolithoautotrophically on hydrogen (3,14,15,19,(21)(22)(23). Members of the genus Desulfosporosinus are found in low-sulfate freshwater and soil environments but also in sulfate-rich heavymetal-contaminated environments, such as acid mine/rock drainage sites.…”

“…Their genomes will give insights into the genetic repertoire and evolution of sulfate reducers typically thriving in terrestrial environments and able to degrade toluene (Desulfosporosinus youngiae), to reduce Fe(III) (Desulfosporosinus meridiei, Desulfosporosinus orientis), and to grow under acidic conditions (Desulfosporosinus acidiphilus).T he sequenced Desulfosporosinus type strains (2,3,14,20) represent four out of eight described species belonging to the genus Desulfosporosinus and cover its phylogenetic and physiological breadth. Besides their ability to reduce sulfate for energy conservation, some Desulfosporosinus species can also grow by using nitrate, Fe(III), or As(V) as terminal electron acceptors or by fermentative processes.…”