title: Haloferax chudinovii sp. nov., a halophilic archaeon from Permian potassium salt deposits.
abstract: Three pigmented strains of halophilic archaea (RS75, RS77, RS79) were isolated from the monoliths of mottled sylvinite from the Verkhnekamsk salt deposit (Solikamsk, Russia). The cells were nonmotile, gram-negative, pleomorphic, disk-shaped or ovoid, 0.8-1.0 × 1.5-2.5 μm. The organism was a chemoorganotrophic obligate aerobe producing catalase and oxidase. A number of carbohydrates and carboxylic acids were used as growth substrates. Growth occurred in the presence of 7-27% NaCl (with the optimum at 15-18%), 0.02-20% KCl (0.2-1%), 0.2-16% MgCl2 (2-3%), in the temperature range from 23 to 51 °C (40-45 °C), and pH 5.5-8.0 (6.8-7.0). The membranes contained carotenoids of the bacterioruberin series. Phosphatidylglyceromethylphosphate (PGP-Me), phosphatidylglycerol (PG), sulfated diglycosyl diether (S-DGD-1) predominated among the polar lipids. The DNA G + C content was 64.0-65.0 mol %. Phylogenetic analysis of the 16S rRNA gene sequences showed high similarity of the new strains to Haloferax species: H. denitrificans (99.2%) and H. volcanii (99.1%), H. larsenii (96.9%) and H. elongans (96.6%). DNA-DNA hybridization revealed 93-95% similarity between strain RS75 and strains RS77 and RS79; the similarity levels between strain RS75 and the type strains of Haloferax denitrificans VKM B-1754(T) and Halobacterium salinarum VKM B-1769(T) were 50 and 10%, respectively. According to its phenotypic and genotypic characteristics, the organism was classified as a member of the genus Haloferax, forming a new species with the proposed name Haloferax chudinovii sp. nov. type strain is RS75(T) (=VKPM B-11279(T)).
authors.affiliation: Institute of Ecology and Genetics of Microorganisms, Ural Branch, Russian Academy of Sciences, Goleva 13, 614081 Perm, Russia. saralov@iegm.ru
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Saralov
authors.forename: Roman V
authors.initials: RV
authors.lastname: Baslerov
authors.forename: Boris B
authors.initials: BB
authors.lastname: Kuznetsov
mesh_terms: D019843:Archaeal Proteins / Q000032:analysis; D001482:Base Composition; D002241:Carbohydrates / Q000032:analysis; D019641:DNA, Archaeal / Q000737:chemistry; D019015:Geologic Sediments / Q000382:microbiology*; D019621:Haloferax / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D008055:Lipids / Q000032:analysis; D010802:Phylogeny; D011188:Potassium; D012800:Siberia
chemical_list: D019843:Archaeal Proteins; D002241:Carbohydrates; D019641:DNA, Archaeal; D008055:Lipids; D011188:Potassium