title: Oligoflexus tunisiensis gen. nov., sp. nov., a Gram-negative, aerobic, filamentous bacterium of a novel proteobacterial lineage, and description of Oligoflexaceae fam. nov., Oligoflexales ord. nov. and Oligoflexia classis nov.
abstract: A phylogenetically novel proteobacterium, strain Shr3(T), was isolated from sand gravels collected from the eastern margin of the Sahara Desert. The isolation strategy targeted bacteria filterable through 0.2-µm-pore-size filters. Strain Shr3(T) was determined to be a Gram-negative, aerobic, non-motile, filamentous bacterium. Oxidase and catalase reactions were positive. Strain Shr3(T) showed growth on R2A medium, but poor or no growth on nutrient agar, trypticase soy agar and standard method agar. The major isoprenoid quinone was menaquinone-7. The dominant cellular fatty acids detected were C16:1ω5c and C16:0, and the primary hydroxy acid present was C12:0 3-OH. The DNA G+C content was 54.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Shr3(T) was affiliated with an uncultivated lineage of the phylum Proteobacteria; the nearest known type strain, with 83% sequence similarity, was Desulfomicrobium orale DSM 12838(T) in the class Deltaproteobacteria. The isolate and closely related environmental clones formed a novel class-level clade in the phylum Proteobacteria with high bootstrap support (96-99%). Based on these results, the novel class Oligoflexia classis nov. in the phylum Proteobacteria and the novel genus and species Oligoflexus tunisiensis gen. nov., sp. nov. are proposed for strain Shr3(T), the first cultivated representative of the Oligoflexia. The type strain of Oligoflexus tunisiensis is Shr3(T) ( = JCM 16864(T) = NCIMB 14846(T)). We also propose the subordinate taxa Oligoflexales ord. nov. and Oligoflexaceae fam. nov. in the class Oligoflexia.
authors.affiliation: Research Fellow of the Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo 102-8471, Japan.|Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Nakai
authors.affiliation: Technical Department, TechnoSuruga Laboratory Co., Ltd., 330 Nagasaki, Shimizu-ku, Shizuoka 424-0065, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nishijima
authors.affiliation: Technical Department, TechnoSuruga Laboratory Co., Ltd., 330 Nagasaki, Shimizu-ku, Shizuoka 424-0065, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Tazato
authors.affiliation: Technical Department, TechnoSuruga Laboratory Co., Ltd., 330 Nagasaki, Shimizu-ku, Shizuoka 424-0065, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Handa
authors.affiliation: Centre of Biotechnology at Sfax, P.O. Box 1177, 3018 Sfax, Tunisia.
authors.forename: Fatma
authors.initials: F
authors.lastname: Karray
authors.affiliation: Centre of Biotechnology at Sfax, P.O. Box 1177, 3018 Sfax, Tunisia.
authors.forename: Sami
authors.initials: S
authors.lastname: Sayadi
authors.affiliation: Alliance for Research on North Africa (ARENA), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Isoda
authors.affiliation: Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8528, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Naganuma
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D003889:Desert Climate; D005227:Fatty Acids / Q000737:chemistry; D006090:Gram-Negative Bacteria / Q000145:classification; D008969:Molecular Sequence Data; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014416:Tunisia; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D024482:Vitamin K 2; C062629:menaquinone 7