Thermostilla marina gen. nov., sp. nov., a thermophilic, facultatively anaerobic planctomycete isolated from a shallow submarine hydrothermal vent.

A novel thermophilic planctomycete (strain SVX8T) was isolated from a shallow submarine hydrothermal vent, Vulcano Island, Italy. The temperature range for growth was 30-68 °C, with an optimum at 55 °C. The pH range for growth was 5.0-9.0, with an optimum at pH 7.0-8.0. Growth was observed at NaCl concentrations ranging from 0.8 to 4.5 % (w/v) with an optimum at 2.5-3.5 % (w/v). The isolate grew anaerobically using a number of mono-, di- and polysaccharides as electron donors and nitrate or elemental sulfur as electron acceptors or by fermentation. Nitrate was reduced to nitrite; sulfur was reduced to sulfide. Strain SVX8T did not grow at atmospheric concentration of oxygen but grew microaerobically (up to 2 % oxygen in the gas phase). The G+C content of the DNA of strain SVX8T was 58.5 mol%. Based on phylogenetic position and phenotypic features, the new isolate is considered to represent a novel species belonging to a new genus in the order Planctomycetales, for which the name Thermostilla marina gen. nov., sp. nov. is proposed. The type strain of Thermostilla marina is SVX8T ( = JCM 19992T = VKM B-2881T). Strain SVX8T is the first thermophilic planctomycete isolated from a marine environment.

Fuchsiella alkaliacetigena gen. nov., sp. nov., an alkaliphilic, lithoautotrophic homoacetogen from a soda lake.

The first alkaliphilic obligately anaerobic hydrogenotrophic homoacetogenic bacterium, strain Z-7100(T), was isolated from sediments of the soda-depositing soda lake Tanatar III (Altay, Russia). Cells were thin, flexible rods, motile, Gram-negative and spore-forming. The organism was an obligate alkaliphile, growing at pH 8.5 to 10.5, with optimum growth at pH 8.8-9.3, and it grew in soda brines containing 1.9-4.7 M total Na(+) (optimum at 2.8-3.3 M). It exhibited an obligate dependence upon sodium carbonate but not upon chloride ions with an NaCl range for growth of 0-14% (w/v) and an optimum at 7.0-8.5% (w/v). The isolate was mesophilic and grew at temperatures from 25 to 45 °C, with an optimum at 40 °C. An H(2)+CO(2) mixture, ethanol, pyruvate and lactate were utilized with the formation of acetate as the sole metabolic product. Carbohydrates and amino acids did not support growth. The isolate had a respiratory type of metabolism, reducing NO3(-), SeO(4)(2-) or anthraquinone-2,6-disulfonate (as electron acceptors with ethanol as an electron donor). It was able to grow chemolithotrophically on H(2)+CO(2) in medium supplemented with a vitamin solution only. The major cellular fatty acids were the saturated fatty acids anteiso-C(15), C(14:0) and C(16:0) and the aldehydes C(16), C(14) and anteiso-C(15). The DNA G+C content of the isolate was 32.0 mol%. 16S rRNA gene sequence analysis showed that strain Z-7100(T) is a member of the order Halanaerobiales and represents a new branch within the family Halobacteroidaceae, clustering with the type strain of Selenihalanaerobacter shriftii (92.9% gene sequence similarity). On the basis of its physiological characteristics and phylogenetic position, the isolate is considered to represent a novel species in a new genus within the family Halobacteroidaceae. The name Fuchsiella alkaliacetigena gen. nov., sp. nov. is proposed. The type strain of the type species is Z-7100(T) (=DSM 24880(T)=VKM B-2667(T)).

Draft genome sequence of the anoxygenic filamentous phototrophic bacterium Oscillochloris trichoides subsp. DG-6.

Oscillochloris trichoides is a mesophilic, filamentous, photoautotrophic, nonsulfur, diazotrophic bacterium which is capable of carbon dioxide fixation via the reductive pentose phosphate cycle and possesses no assimilative sulfate reduction. Here, we present the draft genome sequence of Oscillochloris trichoides subsp. DG-6, the type strain of the species, which has permitted the prediction of genes for carbon and nitrogen metabolism and for the light-harvesting apparatus.