title: Halarchaeum rubridurum sp. nov., a moderately acidophilic haloarchaeon isolated from commercial sea salt samples.
abstract: Six halo-acidophilic archaeal strains were isolated from four commercial salt samples obtained from seawater in the Philippines, Indonesia (Bali) and Japan (Okinawa) on agar plates at pH 4.5. Cells of the six strains were pleomorphic, and stained Gram-negative. Two strains were pink-red pigmented, while four other strains were orange-pink pigmented. Strain MH1-16-3(T) was able to grow at 9-30% (w/v) NaCl [with optimum at 18% (w/v) NaCl], at pH 4.5-6.8 (optimum, pH 5.5) and at 20-50 °C (optimum, 42 °C). The five other strains grew at slightly different ranges. The six strains required at least 1 mM Mg(2+) for growth. The 16S rRNA gene sequences of the six strains were almost identical, sharing 99.9 (1-2 nt differences) to 100% similarity. The closest relatives were Halarchaeum acidiphilum MH1-52-1(T) and Halarchaeum salinum MH1-34-1(T) with 97.7% similarity. The DNA G+C contents of the six strains were 63.2-63.7 mol%. Levels of DNA-DNA relatedness amongst the six strains were 79-86%, while those between MH1-16-3(T) and H. acidiphilum MH1-52-1(T) and H. salinum MH1-34-1(T) were both 43 and 45% (reciprocally), respectively. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the six isolates represent a novel species of the genus Halarchaeum, for which the name Halarchaeum rubridurum sp. nov. is proposed. The type strain is MH1-16-3(T) ( =JCM 16108(T) =CECT 7535(T)).
authors: Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Yuto
authors: Y
authors: Yamauchi
authors: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Hiroaki
authors: H
authors: Minegishi
authors: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Akinobu
authors: A
authors: Echigo
authors: Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, Kanagawa 237-0061, Japan.
authors: Yasuhiro
authors: Y
authors: Shimane
authors: Halophiles Research Institute, 677-1 Shimizu, Noda, Chiba 278-0043, Japan.
authors: Masahiro
authors: M
authors: Kamekura
authors: Japan Collection of Microorganisms, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors: Takashi
authors: T
authors: Itoh
authors: Japan Collection of Microorganisms, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors: Moriya
authors: M
authors: Ohkuma
authors: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.|Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Noriyuki
authors: N
authors: Doukyu
authors: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.|Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Akira
authors: A
authors: Inoue
authors: Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.|Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan.
authors: Ron
authors: R
authors: 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 / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010679:Philippines; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride
chemical_list: D019641:DNA, Archaeal; D008055:Lipids; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride