A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1 T , was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0?6-0?761?2-2?7 mm in size, motile by a single polar flagellum and occurred singly, in pairs or as short spirilla. Growth was observed at 15-48 6C (optimum, 37 6C), >1-7 % NaCl, w/v (optimum, 3 %) and pH 8?0-10?0 (optimum, 9?5). The novel isolate is strictly alkaliphilic, requires a high concentration of carbonate in the growth medium and is obligately anaerobic and catalasenegative. As electron donors, strain MLF1 T uses hydrogen, formate and ethanol. Sulfate, sulfite and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The novel isolate is a lithoheterotroph and a facultative lithoautotroph that is able to grow on hydrogen without an organic source of carbon. Strain MLF1 T is resistant to kanamycin and gentamicin, but sensitive to chloramphenicol and tetracycline. The DNA G+C content is 63?0 mol% (HPLC). DNA-DNA hybridization with the most closely related species, Desulfonatronum lacustre Z-7951 T , exhibited 51 % homology. Also, the genome size (1?6610 9 Da) and T m value of the genomic DNA (71±2 6C) for strain MLF1 T were significantly different from the genome size (2?1610 9 Da) and T m value (63±2 6C) for Desulfonatronum lacustre Z-7951 T . On the basis of physiological and molecular properties, the isolate was considered to be a novel species of the genus Desulfonatronum, for which the name Desulfonatronum thiodismutans sp. nov. is proposed (the type strain is MLF1 T

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Isosphaera pallida (ex Woronichin 1927) Giovannoni et al. 1995 is the type species of the genus Isosphaera. The species is of interest because it was the first heterotrophic bacterium known to be phototactic, and it occupies an isolated phylogenetic position within the Planctomycetaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first complete genome sequence of a member of the genus Isosphaera and the third of a member of the family Planctomycetaceae. The 5,472,964 bp long chromosome and the 56,340 bp long plasmid with a total of 3,763 protein-coding and 60 RNA genes are part of the Genomic Encyclopedia of Bacteria and Archaea project.

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The 16S rRNA gene sequences of 12 strains of Thiobacillus thioparus held by diVerent culture collections have been compared. A deWnitive sequence for the reference type strain (Starkey; ATCC 8158T) was obtained. The sequences for four examples of the Starkey type strain were essentially identical, conWrming their sustained identity after passage through diVerent laboratories. One strain (NCIMB 8454) was reassigned as a strain of Halothiobacillus neapolitanus, and a second (NCIMB 8349) was a species of Thermithiobacillus. These two strains have been renamed in their catalog by the National Collection of Industrial and Marine Bacteria. The 16S rRNA gene sequence of the type strain of Halothiobacillus neapolitanus (NCIMB 8539T) was determined and used to conWrm the identity of other culture collection strains of this species. The reference sequences for the type strains of Thiobacillus thioparus and Halothiobacillus neapolitanus have been added to the online List of Prokaryotic Names with Standing in Nomenclature. Comparison of the 16S rRNA gene sequences available for strains of Thiobacillus denitriWcans indicated that the sequence for the type strain (NCIMB 9548T) should always be use