title: Shewanella arctica sp. nov., an iron-reducing bacterium isolated from Arctic marine sediment.
abstract: Two strains of dissimilatory iron-reducing bacteria, which could couple lactate oxidation to iron reduction for energy conservation, were isolated from Arctic marine sediment. The strains, IR12(T) and IR26, were both Gram-staining-negative, catalase- and oxidase-positive and facultative anaerobes. Their cells were rod-shaped and motile by means of a polar flagellum. Both strains grew in the presence of 0.5-3.5 % (w/v) NaCl, with an absolute requirement for Na(+). Both were psychrotolerant since they could grow at 4-28 °C but had an optimum growth temperature of 20 °C. Both grew at pH 4.5-9.0 (optimum, pH 7.5). The major fatty acids of strains IR12(T) and IR26 were summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c) and C(16 : 0). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains IR12(T) and IR26 belonged to the class Gammaproteobacteria and were most closely related to Shewanella vesiculosa M7(T), Shewanella livingstonensis NF22(T) and Shewanella frigidimarina ACAM 591(T) (with 98.5 and 98.8 %, 98.5 and 98.8 %, and 98.5 and 98.8 % sequence similarities, respectively). The genomic DNA G+C contents of strains IR12(T) and IR26 were 40.0 and 40.3 mol%, respectively. DNA-DNA relatedness data indicated that the two novel strains represented a single species that was distinct from S. vesiculosa M7(T), S. livingstonensis NF22(T) and S. frigidimarina ACAM 591(T). Based on the phylogenetic, phenotypic and DNA-DNA relatedness data, the two new strains represent a single novel species of the genus Shewanella, for which the name Shewanella arctica sp. nov. is proposed. The type strain is IR12(T) ( = KCTC 23109(T) = JCM 16723(T)).
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: So-Jeong
authors: SJ
authors: Kim
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: Soo-Je
authors: SJ
authors: Park
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: Yong-Sik
authors: YS
authors: Oh
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: Sang-Ah
authors: SA
authors: Lee
authors: Biological Resources Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors: Kee-Sun
authors: KS
authors: Shin
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: Dong-Hyun
authors: DH
authors: Roh
authors: Department of Microbiology, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors: Sung-Keun
authors: SK
authors: Rhee
mesh_terms: D000693:Anaerobiosis; D001110:Arctic Regions; D015373:Bacterial Typing Techniques; D001482:Base Composition; D002374:Catalase / Q000032:analysis; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D005407:Flagella / Q000502:physiology; D019015:Geologic Sediments / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism*; D008124:Locomotion; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000032:analysis; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D020592:Shewanella / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D012965:Sodium Chloride / Q000378:metabolism; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D007773:Lactates; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D007501:Iron; D010088:Oxidoreductases; D002374:Catalase