title: Sphingosinicella microcystinivorans gen. nov., sp. nov., a microcystin-degrading bacterium.
abstract: Three strains of bacteria that degrade the cyanobacterial hepatotoxin microcystin, Y2T, MDB2 and MDB3, were isolated from a eutrophic lake, Lake Suwa, and the Tenryu River, Japan, and characterized. These strains were aerobic and chemo-organotrophic and their cells were Gram-negative, non-spore-forming rods, motile by means of single polar flagella. Yellow-pigmented colonies were formed on nutrient agar media. The strains assimilated only citrate among the organic compounds tested as carbon sources. The G+C content of genomic DNA ranged from 63.6 to 63.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolates formed a tight cluster within the family Sphingomonadaceae but were clearly separate from established genera of this family, e.g. Sphingomonas, Sphingobium, Novosphingobium and Sphingopyxis; sequence similarities between the new isolates and type strains from established genera ranged from 90.9 to 94.9 %. Chemotaxonomic and phenotypic data supported the conclusion that these strains were members of the family Sphingomonadaceae. The major components of the cellular fatty acids were 18 : 1omega7c (36-41 %) and 16 : 1omega7c (33-36 %). Hydroxy fatty acids were mainly 2-OH 14 : 0 (11-13 %), and 3-OH fatty acids were absent. Glycosphingolipids were detected. Ubiquinone-10 and homospermidine were present as the major quinine and polyamine, respectively. Thus, it is proposed that the three strains represent a new genus and species of the family Sphingomonadaceae with the name Sphingosinicella microcystinivorans gen. nov., sp. nov. The type strain is Y2T (= KCTC 12019T = JCM 13185T).
authors.affiliation: Marine Works Japan Ltd, Kamariyahigashi, 2-16-32 4F, Kanazawa-ku, Yokohama 236-0042, Japan. maruyamat@mwj.co.jp
authors.forename: Tomoko
authors.initials: T
authors.lastname: Maruyama
authors.forename: Ho-Dong
authors.initials: HD
authors.lastname: Park
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ozawa
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Sumino
authors.forename: Koei
authors.initials: K
authors.lastname: Hamana
authors.forename: Akira
authors.initials: A
authors.lastname: Hiraishi
authors.forename: Kenji
authors.initials: K
authors.lastname: Kato
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism; D001482:Base Composition; D005227:Fatty Acids; D005618:Fresh Water; D006028:Glycosphingolipids; D007564:Japan; D052998:Microcystins; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000378:metabolism*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D042301:Sphingomonadaceae / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology; D014451:Ubiquinone
chemical_list: D001427:Bacterial Toxins; D005227:Fatty Acids; D006028:Glycosphingolipids; D052998:Microcystins; D010456:Peptides, Cyclic; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014451:Ubiquinone; C078588:microcystin