title: Shewanella canadensis sp. nov. and Shewanella atlantica sp. nov., manganese dioxide- and hexahydro-1,3,5-trinitro-1,3,5-triazine-reducing, psychrophilic marine bacteria.
abstract: Two strains belonging to the genus Shewanella, HAW-EB2(T) and HAW-EB5(T), were isolated previously from marine sediment sampled from the Atlantic Ocean, near Halifax harbour in Canada, for their potential to degrade explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). In the present study, strains HAW-EB2(T) and HAW-EB5(T) were found to display high 16S rRNA gene sequence similarity (90-99.5 %) to species of Shewanella, but their gyrB sequences were significantly different from each other and from species of Shewanella (79-87.6 %). Furthermore, DNA-DNA hybridization showed that the genomic DNA of the two strains was only 22 % related and showed less than 41 % relatedness to closely related species of Shewanella. In comparison to other species of Shewanella, strains HAW-EB2(T) and HAW-EB5(T) were also unique in some phenotypic properties such as activities of beta-galactosidase and tyrosine arylamidase and the ability to metabolize certain organic acids and sugars. Both strains HAW-EB2(T) and HAW-EB5(T) utilize malate, valerate, peptone and yeast extract as sole carbon and energy sources. The major membrane fatty acids of the two strains were C(14 : 0), iso-C(15 : 0), C(16 : 0), C(16 : 1)omega7, C(18 : 1)omega7 and C(20 : 5)omega3 and their major quinones were Q-7, Q-8 and MK-7. On the basis of these results, strain HAW-EB2(T) (=NCIMB 14238(T) =CCUG 54553(T)) is proposed as the type strain of Shewanella canadensis sp. nov. and strain HAW-EB5(T) (=NCIMB 14239(T) =CCUG 54554(T)) is proposed as the type strain of Shewanella atlantica sp. nov.
authors.affiliation: Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Ave, Montreal, Quebec H4P 2R2, Canada.
authors.forename: Jian-Shen
authors.initials: JS
authors.lastname: Zhao
authors.affiliation: Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Ave, Montreal, Quebec H4P 2R2, Canada.
authors.forename: Dominic
authors.initials: D
authors.lastname: Manno
authors.affiliation: Defence Research and Development Canada, 2459 Pie IX Boulevard, Valcartier, Quebec G3J 1X5, Canada.
authors.forename: Sonia
authors.initials: S
authors.lastname: Thiboutot
authors.affiliation: Defence Research and Development Canada, 2459 Pie IX Boulevard, Valcartier, Quebec G3J 1X5, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Ampleman
authors.affiliation: Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Ave, Montreal, Quebec H4P 2R2, Canada.
authors.forename: Jalal
authors.initials: J
authors.lastname: Hawari
mesh_terms: D001267:Atlantic Ocean; D015373:Bacterial Typing Techniques; D002170:Canada; D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry; D027081:DNA Gyrase / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D020459:Genes, rRNA; D019015:Geologic Sediments / Q000382:microbiology; D017895:Manganese Compounds / Q000378:metabolism*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010087:Oxides / Q000378:metabolism*; D010802:Phylogeny; D011809:Quinones / Q000032:analysis; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D020592:Shewanella / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism*; D014227:Triazines / Q000378:metabolism*; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D002264:Carboxylic Acids; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D017895:Manganese Compounds; D010087:Oxides; D011809:Quinones; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014227:Triazines; D002244:Carbon; D001616:beta-Galactosidase; D027081:DNA Gyrase; C016552:manganese dioxide; C009160:cyclonite