Desulfonatronobacter acidivorans gen. nov., sp. nov. and Desulfobulbus alkaliphilus sp. nov., haloalkaliphilic heterotrophic sulfate-reducing bacteria from soda lakes

Abstract

Two types of heterotrophic sulfate-reducing bacteria (SRB) were isolated from anoxic sediments of hypersaline soda lakes in Kulunda Steppe (Altai, Russia). The isolates used propionate as an energy and carbon source. Strain APT2T was enriched and isolated with thiosulfate as the electron acceptor. Strains APS1T and ASS1 were isolated with sulfate. Strain APT2T was a short rod and motile with a single subpolar flagellum, while strains APS1T and ASS1 were lemon-shaped oval rods and motile with a single polar flagellum and thin flagella-like filaments. Strain APT2T grew by complete oxidation of C3–C8 fatty acids with thiosulfate or sulfate as the electron acceptor, while strains APS1T and ASS1 were much less versatile and utilized only propionate and pyruvate as the electron donor and carbon source with sulfate or sulfite as the electron acceptor. Furthermore, strains APS1T and ASS1 oxidized propionate incompletely to form acetate. All of the isolates were moderately halophilic and obligately alkaliphilic. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolates in the order Desulfobacterales of the class Deltaproteobacteria . Strain APT2T belonged to the family Desulfobacteraceae and clustered with a halophilic SRB, Desulfosalsimonas propionicica PropAT. Strains APS1T and ASS1 were closely related to each other and clustered with the genus Desulfobulbus of the family Desulfobulbaceae . On the basis of phenotypic and phylogenetic analysis, the isolates are proposed to represent two novel taxa, Desulfonatronobacter acidivorans gen. nov., sp. nov. (type strain of the type species APT2T = DSM 24257T = UNIQEM U853T) and Desulfobulbus alkaliphilus sp. nov. (type strain APS1T = DSM 24258T = UNIQEM U900T).

The Family Desulfobacteraceae

“…A detailed description is provided by Widdel and Bak (1992) and might be modified by other authors as listed in the original descriptions of various taxa. Typical modifications are simplifications, higher salt concentrations, or media for cultivation of haloalkaline organisms (e.g., Sorokin et al 2012). For the isolation of organisms from brackish and marine sediment an elevated concentration of Mg 2+ and sometimes Ca 2+ ions is required.…”

“…The type strain of Desulfonatronobacter acidivorans, strain APT2, was isolated with propionate as electron donor and carbon source and thiosulfate as electron acceptor from anoxic sediment of lake Bitter 1, a soda lake in southwestern Siberia (Altai region, Russia) (Sorokin et al 2012).…”

“…The family Desulfobacteraceae contains the genera Desulfobacter (Widdel 1981) which is the type genus of the family (Kuever et al 2006) Desulfatibacillum (Cravo-Laureau et al 2004a), Desulfatiferula (Cravo-Laureau et al 2007), Desulfatirhabdium (Balk et al 2008), Desulfatitalea (Higashioka et al 2012), Desulfobacterium (Bak und Widdel et al 1988), Desulfobacula (Rabus et al 2000;Kuever et al 2001), Desulfobotulus (Kuever et al 2009), Desulfocella (Brandt et al 1999), Desulfococcus (Widdel 1981), Desulfoconvexum (Könneke et al 2012), Desulfofaba (Knoblauch et al 1999), Desulfofrigus (Knoblauch et al 1999), Desulfoluna (Suzuki et al 2008), Desulfonatronobacter (Sorokin et al 2012), Desulfonema (Widdel 1981), Desulforegula (Rees and Patel 2001), Desulfosalsimonas (Kjeldsen et al 2010), Desulfosarcina (Widdel 1981), Desulfospira , and Desulfotignum (Kuever et al 2001). Gram-staining negative.…”

The Family Desulfobulbaceae

“…The type strain of the genus Desulfobulbus strain 1pr3 was isolated using propionate as electron donor from anoxic mud of a freshwater ditch located at Lindhorst close to Hannover, Northern Germany (Widdel 1980). Strain APS1 (type strain of Desulfobulbus alkaliphilus) was isolated also with propionate from sediment of a soda lake located in the Altai region, Russia (Sorokin et al 2012). The source for Desulfobulbus elongatus was a mesophilic anaerobic digester fed with vegetable canning waste water (Samain et al 1984).…”

Insights into the Evolution of Host Association through the Isolation and Characterization of a Novel Human Periodontal Pathobiont,Desulfobulbus oralis

“…As with other oral species, it has remained unclear if those organisms play a role in the etiology of periodontitis or their increased abundance is a consequence of the disease state, with deep subgingival pockets favoring the proliferation of strict anaerobes. No host-associated species of Desulfobulbus has been cultivated so far, although multiple free-living relatives have been isolated and characterized from aquatic and sediment samples (23)(24)(25)(26)(27)(28)(29). All free-living Desulfobulbus species are sulfate reducers, strict anaerobes, largely prototrophic, and use a variety of electron donors and acceptors.…”