Inmirania thermothiophila gen. nov., sp. nov., a thermophilic, facultatively autotrophic, sulfur-oxidizing gammaproteobacterium isolated from a shallow-sea hydrothermal vent

Abstract

Inmirania thermothiophila gen. nov., sp. nov., a thermophilic, facultatively autotrophic, sulfur-oxidizing gammaproteobacterium isolated from a shallow-sea hydrothermal vent , was isolated from a thermal spring located in a tidal zone of a geothermally heated beach (Kuril Islands, Russia). Cells of strain S2479T were rod-shaped and motile with a Gram-negative cell-wall type. The temperature range for growth was 35-68 8C (optimum 65 8C), and the pH range for growth was pH 5.5-8.8 (optimum pH 6.5). Growth of strain S2479 T was observed in the presence of NaCl concentrations ranging from 0.5 to 3.5 % (w/v) (optimum 1.5-2.0 %). The strain oxidized sulfur and thiosulfate as sole energy sources for autotrophic growth under anaerobic conditions with nitrate as electron acceptor. Strain S2479 T was also capable of heterotrophic growth by reduction of nitrate with oxidation of low-chain fatty acids and a limited number of other carboxylic acids or with complex proteinaceous compounds. Nitrate was reduced to N 2 . Sulfur compounds were oxidized to sulfate. Strain S2479 T did not grow aerobically during incubation at atmospheric concentration of oxygen but was able to grow microaerobically (1 % of oxygen in gas phase). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain was a member of the family Ectothiorhodospiraceae, order Chromatiales, class Gammaproteobacteria. On the basis of phylogenetic and phenotypic properties, strain S2479 T represents a novel species of a new genus, for which the name Inmirania thermothiophila gen. nov., sp. nov. is proposed. The type strain of the type species is S2479

Minireview: demystifying microbial reaction energetics

“…Clearly, if the sign (and value) of was meaningful, this reaction, in the direction as written, would be impossible. However, this is a documented catabolism carried out by members of the Deltaproteobacteria, Thermodesulfobacteria and other bacterial phyla (Bak and Pfennig, ; Finster et al ., ; Slobodkin et al ., ; Kojima et al ., ; Slobodkina et al ., ). In environments with low levels of sulphide and sulphate and circumneutral to alkaline pH, the Q ‐term for has a large negative value that can counter the positive value of , resulting in a net negative value of ΔG 11 .…”

Alkalibaculum sporogenes sp. nov., isolated from a terrestrial mud volcano and emended description of the genus Alkalibaculum

“…Culture purity was confirmed by monitoring of cell morphology using bright-field microscopy, as well as by the absence of cells that were morphologically different from strain M08 DMB T during growth in peptone-yeast extract-glucose liquid medium. Light and electron microscopy, physiological studies on substrate and electron acceptor utilization, temperature, pH and salinity ranges for growth, analytical techniques for determination of metabolic products, determination of DNA G+C content and cellular fatty acid composition analysis were performed as previously described [5]. Oxidase and catalase activities were measured as described in [6,7].…”

“…Genomic DNA isolation and 16S rRNA gene amplification and sequencing were performed as described previously [5]. The 16S rRNA gene sequence of the isolate was compared with other sequences in GenBank [14] by using the blast program [15] and by means of the EzBioCloud server [16] ( www.…”

Description of Immundisolibacter cernigliae gen. nov., sp. nov., a high-molecular-weight polycyclic aromatic hydrocarbon-degrading bacterium within the class Gammaproteobacteria, and proposal of Immundisolibacterales ord. nov. and Immundisolibacteraceae fam. nov.

“…Some of the closest described relatives to TR3.2 T based on 16S rRNA gene similarity (Fig. 2) were M. capsulatus strain Bath (90.5 % similarity) [17], M. capsulatus strain ATCC 19069 T (strain Texas; 90.2 %), 'Thioalkalivibrio sulfidophilus' strain HL-EbGr7 (90.1 %) [32] and Inmirania thermothiophila strain S2479 T (90.3 %) [33]. An estimate of DNA-DNA hybridization using the complete genome of strain TR3.2 T compared to those of M. capsulatus Bath and 'Thioalkalivibrio sulfidophilus' HL-EbGr7 with the genometo-genome distance calculator [34] predicted a DNA-DNA hybridization value of 18.5 % to both organisms using the recommended formula.…”

“…While isolated under mesophilic and low salinity conditions, Thiocystis organisms grow optimally in anoxic or microoxic conditions either photolithotrophically or chemoautotrophically [40]. Inmirania thermothiophila is a facultatively anaerobic autotroph that grows optimally at high temperatures and salinity [33]. Members of the genus Nitrosococcus are marine, ammonia-oxidizing chemolithotrophs [41,42].…”