title: Halarchaeum nitratireducens sp. nov., a moderately acidophilic haloarchaeon isolated from commercial sea salt.
abstract: Two halophilic moderately acidophilic archaeal strains, MH1-136-2(T) and MH1-370-1 were isolated from commercial salt samples made from seawater in Japan and Indonesia, respectively. Cells of the two strains were pleomorphic and Gram-stain-negative. Strain MH1-136-2(T) was pink pigmented, while MH1-370-1 was orange-red pigmented. Strain MH1-136-2(T) was able to grow at 9-30 % (w/v) NaCl (with optimum, 21 % NaCl, w/v) at pH 4.5-6.2 (optimum, pH 5.2-5.5) and at 18-55 °C (optimum, 45 °C). Strain MH1-370-1 was able to grow at 12-30 % (w/v) NaCl (optimum, 18 %, w/v) at pH 4.2-6.0 (optimum, pH 5.2-5.5) and 20-50 °C (optimum, 45 °C). Strain MH1-136-2(T) required at least 1 mM Mg(2+), while MH1-370-1 required at least 10 mM for growth. Both strains reduced nitrate and nitrite under aerobic conditions. The 16S rRNA gene sequences of strains MH1-136-2(T) and MH1-370-1 were identical, and the closest relative was Halarchaeum rubridurum MH1-16-3(T) with 98.3 % similarity. The level of DNA-DNA relatedness between these strains was 90.9 % and 92.4 % (reciprocally), while that between MH1-136-2(T) and Halarchaeum acidiphilum MH1-52-1(T), Halarchaeum salinum MH1-34-1(T) and Halarchaeum rubridurum MH1-16-3(T) was 37.7 %, 44.3 % and 41.1 % (each an average), respectively. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the isolates represent a novel species of the genus Halarchaeum, for which the name Halarchaeum nitratireducens sp. nov. is proposed. The type strain is MH1-136-2(T) ( = JCM 16331(T) = CECT 7573(T)) isolated from solar salt produced in Japan.
authors.affiliation: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Minegishi
authors.affiliation: Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Yuto
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Bio-Nano Electronics Research Center, 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, 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, 3-1-1 Koyadai, Tsukuba, 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, Ibaraki 305-0074, Japan.
authors.forename: Moriya
authors.initials: M
authors.lastname: Ohkuma
authors.affiliation: Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.|Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors.forename: Ron
authors.initials: R
authors.lastname: Usami
mesh_terms: D001482:Base Composition; D019641:DNA, Archaeal / Q000235:genetics; D006216:Halobacteriaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D007214:Indonesia; D007564:Japan; D008055:Lipids / Q000737:chemistry; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D010858:Pigmentation; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D012965:Sodium Chloride
chemical_list: D019641:DNA, Archaeal; D008055:Lipids; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride