title: Thiomicrospira halophila sp. nov., a moderately halophilic, obligately chemolithoautotrophic, sulfur-oxidizing bacterium from hypersaline lakes.
abstract: Enrichments at 2 M NaCl and pH 7.5-8, with thiosulfate or sulfide as electron donor, inoculated with sediments from hypersaline chloride-sulfate lakes of the Kulunda Steppe (Altai, Russia) resulted in the domination of two different groups of moderately halophilic, chemolithoautotrophic, sulfur-oxidizing bacteria. Under fully aerobic conditions with thiosulfate, bacteria belonging to the genus Halothiobacillus dominated while, under microaerophilic conditions, a highly motile, short vibrio-shaped phenotype outcompeted the halothiobacilli. Three genetically and phenotypically highly similar vibrio-shaped isolates were obtained in pure culture and one of them, strain HL 5(T), was identified as a member of the Thiomicrospira crunogena cluster by 16S rRNA gene sequencing. The new isolates were able to grow with thiosulfate as electron donor within a broad salinity range from 0.5 to 3.5 M NaCl with an optimum at 1.5 M and within a pH range from 6.5 to 8.5 with an optimum at pH 7.5-7.8. Comparative analysis of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) gene sequences demonstrated that strain HL 5(T) possessed two genes, cbbL-1 and cbbL-2, of the form I RuBisCO and a cbbM gene of the form II RuBisCO, similar to the other members of the Thiomicrospira crunogena cluster. On the basis of phenotypic and genetic comparison, the new halophilic isolates are proposed to be placed into a novel species, Thiomicrospira halophila sp. nov. (type strain HL 5(T)=DSM 15072(T)=UNIQEM U 221(T)).
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.|Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/2, 117811 Moscow, Russia.
authors.forename: Dimitry Yu
authors.initials: DY
authors.lastname: Sorokin
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-let Octyabrya 7/2, 117811 Moscow, Russia.
authors.forename: Tatjana P
authors.initials: TP
authors.lastname: Tourova
authors.affiliation: Bioengineering Center, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Tatjana V
authors.initials: TV
authors.lastname: Kolganova
authors.affiliation: Department of Microbiology, Faculty of Biology, Moscow State University, Moscow, Russia.
authors.forename: Elizaveta M
authors.initials: EM
authors.lastname: Spiridonova
authors.affiliation: Department of Microbiology, Faculty of Biology, Moscow State University, Moscow, Russia.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Berg
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
authors.forename: Gerard
authors.initials: G
authors.lastname: Muyzer
mesh_terms: D015373:Bacterial Typing Techniques; D004275:DNA, Ribosomal / Q000032:analysis; D005618:Fresh Water / Q000382:microbiology*; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010641:Phenotype; D010802:Phylogeny; D044147:Piscirickettsiaceae / Q000145:classification* / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D012336:RNA, Ribosomal, 16S; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics; D012426:Russia; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride; D013045:Species Specificity; D013455:Sulfur / Q000378:metabolism*
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D013455:Sulfur; D012273:Ribulose-Bisphosphate Carboxylase