title: Halocalculus aciditolerans gen. nov., sp. nov., an acid-tolerant haloarchaeon isolated from commercial salt.
abstract: Three halophilic archaeal strains, MH2-243-1(T), MH2-93-1 and MH2-91-1 were isolated from commercial salt samples from Japan, Australia, and Bolivia. Strain MH2-243-1(T) was able to grow in the presence of 12-30% (w/v) NaCl (optimum, 18% NaCl), at pH 4.5-7.0 (optimum, pH 6.0) and at 20-60 °C (optimum, 40 °C). Strains MH2-91-1 and MH2-93-1 grew in slightly different ranges. The orthologous 16S rRNA gene sequences of the three strains were almost identical (99.8-99.9% similarities), and the closest relative was Salarchaeum japonicum JCM 16327(T) with 94.2-94.3% 16S rRNA gene sequence similarities, followed by strains of members of the closely related genera Halobacterium and Halarchaeum . The RNA polymerase subunit B' gene (rpoB') sequence also showed the highest similarity (86.6%) to that of Salarchaeum japonicum JCM 16327(T). The DNA G+C contents of strains MH2-243-1(T), MH2-93-1 and MH2-91-1 were 68.5, 68.8 and 68.3 mol%, respectively. DNA-DNA relatedness values amongst the three strains were 97-99%. The polar lipids of the three strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and at least seven unidentified glycolipids. The polar lipid composition differed from those of Salarchaeum japonicum and species of the genera Halobacterium and Halarchaeum . Based on the phenotypic and phylogenetic analyses, it is proposed that the isolates represent a novel species of a new genus, for which the name Halocalculus aciditolerans gen. nov., sp. nov. is proposed. The type strain of the type species is MH2-243-1(T) ( = JCM 19596(T) =KCTC 4149(T)) isolated from solar salt produced in Japan. MH2-93-1 ( = JCM 19595) and MH2-91-1 ( = JCM 19594) are additional strains of the type species.
authors.affiliation: Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka-shi, Kanagawa 237-0061, Japan.|Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.|Research Institute of Industrial Technology, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minegishi
authors.affiliation: Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.|Research Institute of Industrial Technology, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Echigo
authors.affiliation: Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Kuwahara
authors.affiliation: Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka-shi, Kanagawa 237-0061, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimane
authors.affiliation: Halophiles Research Institute, 677-1 Shimizu, Noda-shi, Chiba 278-0043, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kamekura
authors.affiliation: Japan Collection of Microorganisms, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba-shi, Ibaraki 305-0074, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Japan Collection of Microorganisms, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba-shi, Ibaraki 305-0074, Japan.
authors.forename: Moriya
authors.initials: M
authors.lastname: Ohkuma
authors.affiliation: Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.|Research Institute of Industrial Technology, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama 350-8585, Japan.
authors.forename: Ron
authors.initials: R
authors.lastname: Usami
mesh_terms: D001315:Australia; D001838:Bolivia; D019641:DNA, Archaeal / Q000235:genetics; D019766:Genes, Archaeal; D006017:Glycolipids / Q000737:chemistry; D006216:Halobacteriaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D007564:Japan; D008055:Lipids / Q000737:chemistry; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride
chemical_list: D019641:DNA, Archaeal; D006017:Glycolipids; D008055:Lipids; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride