Desulfoluna butyratoxydans gen. nov., sp. nov., a novel Gram-negative, butyrate-oxidizing, sulfate-reducing bacterium isolated from an estuarine sediment in Japan

Abstract

Desulfoluna butyratoxydans gen. nov., sp. nov., a novel Gram-negative, butyrate-oxidizing, sulfatereducing bacterium isolated from an estuarine sediment in Japan Daisuke Suzuki, Atsuko Ueki, Aya Amaishi3 and Katsuji Ueki Correspondence Atsuko Ueki uatsuko@tds1.tr.yamagata-u.ac.jp Faculty of Agriculture, Yamagata University, Wakaba-machi 1-23, Tsuruoka, Yamagata 997-8555, Japan A strictly anaerobic, mesophilic, sulfate-reducing bacterial strain, designated MSL71 T , was isolated from an estuarine sediment from the Sea of Japan bordering the Japanese islands and was characterized phenotypically and phylogenetically. The cells were found to be Gram-negative, motile, non-spore-forming, slightly curved rods. Catalase and oxidase activities were not detected. The optimum NaCl concentration for growth was 2.0 % (w/v), the optimum temperature was 30 6C and the optimum pH was 6.3. Strain MSL71 T utilized formate, butyrate, pyruvate, lactate, malate, ethanol, propanol, butanol, glycerol and H 2 as electron donors for sulfate reduction. The organic electron donors used were incompletely oxidized, mainly to acetate. The strain did not use acetate, propionate, fumarate, succinate, methanol, glycine, alanine, serine, aspartate or glutamate. Sulfite and thiosulfate were used as electron acceptors with lactate as an electron donor, but fumarate was not utilized. Without electron acceptors, pyruvate and malate, but not lactate or fumarate, were fermented. The genomic DNA G+C content was 62.0 mol%. Menaquinone MK-8(H 4 ) was the major respiratory quinone. The major cellular fatty acids were C 14 : 0 , C 16 : 0 , C 16 : 1 v7, C 18 : 1 v9, C 18 : 1 v7 and C 14 : 0 3-OH. A phylogenetic analysis based on the 16S rRNA gene sequence placed the strain in the class Deltaproteobacteria. The closest recognized relative of strain MSL71 T was Desulfofrigus fragile (93.9 % sequence similarity) and the next closest recognized species was Desulfofrigus oceanense (93.5 %). On the basis of the significant differences in the 16S rRNA gene sequence and phenotypic characteristics between strain MSL71 T and each of the related species, a novel genus and species, Desulfoluna butyratoxydans gen. nov., sp. nov., are proposed to accommodate strain MSL71 T . The type strain is MSL71 T (5JCM 14721 T 5DSM 19427 T ).Sulfate-reducing bacteria (SRB) are capable of utilizing various compounds, such as H 2 , fatty acids, alcohols, amino acids and sugars, as well as aliphatic and aromatic hydrocarbons, as electron donors for sulfate reduction (Hansen, 1993;Castro et al., 2000;Rabus et al., 2000). Major intermediates of anaerobic decomposition of organic matter, such as formate, acetate, propionate, butyrate, lactate and H 2 , serve as the most important electron donors for sulfate reduction, and thus SRB contribute significantly to the mineralization of organic matter and the sulfur cycle (Sørensen et al., 1981;Jørgensen, 1982). In the course of an investigation of SRB in an estuarine sediment from the Japanese islands, we isolated various strains of phylogenetic...

The Family Desulfobacteraceae

“…The type strain of Desulfoluna butyratoxydans, strain MSL7, was isolated from estuarine sediment at the Niida River estuary in Sakata Harbour, Japan, using lactate as substrate (Suzuki et al 2008). A sponge (Aplysina aerophoba) from the Mediterranean Sea (Banyuls sur Mer, France) was used as inoculum for the isolation of strain AA1, the type strain of Desulfoluna spongiiphila, with lactate as electron donor and carbon source (Ahn et al 2009).…”

“…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.…”

Desulfoluna spongiiphila sp. nov., a dehalogenating bacterium in the Desulfobacteraceae from the marine sponge Aplysina aerophoba

“…Desulfoluna butyratoxydans MSL71 T was isolated from estuarine sediment and the optimum growth temperature is 30 u C (Suzuki et al, 2008). In addition, Desulfoluna butyratoxydans MSL71 T is not able to dehalogenate 2,6-dibromophenol or to utilize citrate or glucose as electron donor, in contrast to strain AA1 T .…”

Desulfovibrio butyratiphilus sp. nov., a Gram-negative, butyrate-oxidizing, sulfate-reducing bacterium isolated from an anaerobic municipal sewage sludge digester

“…However, in the presence of sulfate as an electron acceptor, some sulfate-reducing bacterial species oxidize butyrate either completely to CO 2 or incompletely to acetate (Rabus et al, 2000). These sulfate-reducing bacterial species belong to the families Desulfobacteraceae (Cravo-Laureau et al, 2004;Kuever et al, 2005;Balk et al, 2008;Suzuki et al, 2008), Desulfohalobiaceae (Belyakova et al, 2006) and Syntrophobacteraceae (Beeder et al, 1995;Sievert & Kuever, 2000;Tanaka et al, 2000) in the class Deltaproteobacteria or to the genus Desulfotomaculum in the phylum Firmicutes (Daumas et al, 1988;Tasaki et al, 1991; Fardeau et al, 1995;Kuever et al, 1999;Vandieken et al, 2006).In the present study, we isolated five sulfate-reducing bacterial strains (BSY T , BSY-C, BST, BST-B and BST-C) from two anaerobic municipal sewage sludge digesters via enrichment cultures. All strains reduced sulfate with Abbreviation: DSR, dissimilatory sulfite-reductase.…”