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

Abstract

Strictly anaerobic, mesophilic, sulfate-reducing bacterial strains were isolated from two anaerobic municipal sewage sludge digesters. One representative strain (BSY T ) was characterized phenotypically and phylogenetically. Cells were Gram-negative, motile by means of a single polar flagellum, non-spore-forming, curved rods. Cells had desulfoviridin and cytochrome type c. Catalase and oxidase activities were not detected. The optimum NaCl concentration for growth was 0.5 % (w/v). The optimum temperature was 35 6C and the optimum pH was 7.1. Strain BSY T utilized butyrate, 2-methylbutyrate, valerate, pyruvate, lactate, ethanol, 1-propanol, butanol and H 2 as electron donors for sulfate reduction. This strain grew lithoautotrophically with H 2 /CO 2 under sulfate-reducing conditions. Most organic electron donors were incompletely oxidized to mainly acetate, whereas 2-methylbutyrate and valerate were oxidized to equivalent amounts of acetate and propionate. Strain BSY T utilized thiosulfate as an electron acceptor, and grew with pyruvate in the absence of electron acceptors. The genomic DNA G+C content of strain BSY T was 63.3 mol%. Menaquinone MK-6(H 2 ) was the major respiratory quinone. Major cellular fatty acids were C 14 : 0 , C 16 : 0 , C 16 : 1 v7 and C 18 : 1 v7. Phylogenetic analyses based on 16S rRNA and dissimilatory sulfite-reductase b-subunit gene sequences assigned strain BSY T to the genus Desulfovibrio in the family Desulfovibrionaceae within the class Deltaproteobacteria. Its closest recognized relative based on 16S rRNA gene sequences was the type strain of Desulfovibrio putealis (95.3 % similarity). On the basis of significant differences in 16S rRNA gene sequences and phenotypic characteristics, the sewage sludge strains are considered to represent a single novel species of the genus Desulfovibrio, for which the name Desulfovibrio butyratiphilus sp. nov. is proposed. The type strain is BSY T (5JCM 15519 T 5DSM 21556 T ).Butyrate is an important intermediate in the anaerobic degradation of organic matter in various anaerobic ecosystems. Because the oxidation of butyrate is usually thermodynamically unfavourable under anaerobic conditions, it is generally degraded by syntrophic interactions between H 2 -producing acetogenic bacteria and H 2 -utilizing methanogens in methanogenic conditions (Stams, 1994;Schink, 1997;Sekiguchi et al., 2000;Zhang et al., 2004). 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., 1...

An HcpR paralog ofDesulfovibrio gigas provides protection against nitrosative stress

“…3 ) generally agree with the results of previous studies in Desulfovibrio (e.g. [50–52] ). Comparison of the topological relationships of the Desulfovibrio species in the 16S rRNA tree ( Fig.…”

“…The relationships shown in the 16S rRNA phylogeny (Fig. 3) generally agree with the results of previous studies in Desulfovibrio (e.g [50–52]…”

Determination of Microbial Maintenance in Acetogenesis and Methanogenesis by Experimental and Modeling Techniques

“…A literature survey (Supplementary Table S2, Supplementary Material A) provides first hints on which of the taxa might be responsible for VFA oxidation and which ones might be responsible for degradation of dead microbial biomass. Cloacimonetes (Pelletier et al, 2008; Juste-Poinapen et al, 2015; Ahlert et al, 2016), Cryptanaerobacter (de Bok et al, 2005), and Desulfovibrio (Suzuki et al, 2010) have been connected with propionic or butyric acid oxidation but no co-culture of one of their species with a hydrogenotrophic methanogen has been tested yet. Candidatus Cloacamonas acidaminovorans, for example, contains all genes for propionic acid oxidation via methylmalonyl-CoA but has not been isolated yet (Pelletier et al, 2008).…”

Micro-Oxygenation in Upflow Anaerobic Sludge Bed (UASB) Reactors Using a Silicon Membrane for Sulfide Oxidation

“…Another potential route of oxygen consumption could be the establishment of a cycle of oxidation/reduction of sulfur in the membrane module/reactor system. Sulfate reducing bacteria can use sulfate, thiosulfate, or even sulfite as an electron acceptor in the process of dissimilatory sulfate reduction by SRB [ 27 , 28 , 29 ]. Therefore, there is a chance that the production of oxidized sulfur products, generated by SOB, triggered a new reduction process, causing a higher consumption of oxygen.…”