title: Halobaculum magnesiiphilum sp. nov., a magnesium-dependent haloarchaeon isolated from commercial salt.
abstract: Two extremely halophilic archaea, strains MGY-184(T) and MGY-205, were isolated from sea salt produced in Japan and rock salt imported from Bolivia, respectively. Both strains were pleomorphic, non-motile, Gram-negative and required more than 5 % (w/v) NaCl for growth, with optimum at 9-12 %, in the presence of 2 % (w/v) MgCl2 . 6H2O. In the presence of 18 % (w/v) MgCl2 . 6H2O, however, both strains showed growth even at 1.0 % (w/v) NaCl. Both strains possessed two 16S rRNA genes (rrnA and rrnB), and they revealed closest similarity to Halobaculum gomorrense JCM 9908(T), the single species with a validly published name of the genus Halobaculum, with similarity of 97.8 %. The rrnA and rrnB genes of both strains were 100 % similar. The rrnA genes were 97.6 % similar to the rrnB genes in both strains. DNA G+C contents of strains MGY-184(T) and MGY-205 were 67.0 and 67.4 mol%, respectively. Polar lipid analysis revealed that the two strains contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester derived from C20C20 archaeol. The DNA-DNA hybridization value between the two strains was 70 % and both strains showed low levels of DNA-DNA relatedness (48-50 %) with Halobaculum gomorrense JCM 9908(T). Physiological and biochemical characteristics allowed differentiation of strains MGY-184(T) and MGY-205 from Halobaculum gomorrense JCM 9908(T). Therefore, strains MGY-184(T) and MGY-205 represent a novel species of the genus Halobaculum, for which the name Halobaculum magnesiiphilum sp. nov. is proposed; the type strain is MGY-184(T) ( = JCM 17821(T) = KCTC 4100(T)).
authors.affiliation: Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Shimoshige
authors.affiliation: Department of Biological Applied Chemistry, Graduate School of Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minegishi
authors.affiliation: Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Echigo
authors.affiliation: Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimane
authors.affiliation: Halophiles Research Institute, 677-1 Shimizu, Noda, Chiba 278-0043, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kamekura
authors.affiliation: Japan Collection of Microorganisms, RIKEN BioResource Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.|Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Ron
authors.initials: R
authors.lastname: Usami
mesh_terms: D001482:Base Composition; D001838:Bolivia; D019641:DNA, Archaeal / Q000235:genetics; D006216:Halobacteriaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D007564:Japan; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010715:Phosphatidylglycerols / Q000032:analysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride
chemical_list: D019641:DNA, Archaeal; D010715:Phosphatidylglycerols; D012336:RNA, Ribosomal, 16S; C034358:phosphatidylglycerophosphate; D012965:Sodium Chloride; D008274:Magnesium