title: Paucibacter toxinivorans gen. nov., sp. nov., a bacterium that degrades cyclic cyanobacterial hepatotoxins microcystins and nodularin.
abstract: Thirteen bacterial isolates from lake sediment, capable of degrading cyanobacterial hepatotoxins microcystins and nodularin, were characterized by phenotypic, genetic and genomic approaches. Cells of these isolates were Gram-negative, motile by means of a single polar flagellum, oxidase-positive, weakly catalase-positive and rod-shaped. According to phenotypic characteristics (carbon utilization, fatty acid and enzyme activity profiles), the G+C content of the genomic DNA (66.1-68.0 mol%) and 16S rRNA gene sequence analysis (98.9-100% similarity) the strains formed a single microdiverse genospecies that was most closely related to Roseateles depolymerans (95.7-96.3% 16S rRNA gene sequence similarity). The isolates assimilated only a few carbon sources. Of the 96 carbon sources tested, Tween 40 was the only one used by all strains. The strains were able to mineralize phosphorus from organic compounds, and they had strong leucine arylamidase and chymotrypsin activities. The cellular fatty acids identified from all strains were C(16:0) (9.8-19%) and C(17:1)omega7c (<1-5.8%). The other predominant fatty acids comprised three groups: summed feature 3 (<1-2.2%), which included C(14:0) 3-OH and C(16:1) iso I, summed feature 4 (54-62%), which included C(16:1)omega7c and C(15:0) iso OH, and summed feature 7 (8.5-28%), which included omega7c, omega9c and omega12t forms of C(18:1). A more detailed analysis of two strains indicated that C(16:1)omega7c was the main fatty acid. The phylogenetic and phenotypic features separating our strains from recognized bacteria support the creation of a novel genus and species, for which the name Paucibacter toxinivorans gen. nov., sp. nov. is proposed. The type strain is 2C20(T) (=DSM 16998(T)=HAMBI 2767(T)=VYH 193597(T)).
authors: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland.
authors: Jarkko
authors: J
authors: Rapala
authors: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland.
authors: Katri A
authors: KA
authors: Berg
authors: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland.
authors: Christina
authors: C
authors: Lyra
authors: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland.
authors: R Maarit
authors: RM
authors: Niemi
authors: Fachgebiet Ökologie der Mikroorganismen, Institut für Technischen Umweltschutz, Technische Universität Berlin, D-10587 Berlin, Germany.
authors: Werner
authors: W
authors: Manz
authors: Institute of Biotechnology, PO Box 56, FIN-00014 University of Helsinki, Finland.
authors: Sini
authors: S
authors: Suomalainen
authors: Institute of Biotechnology, PO Box 56, FIN-00014 University of Helsinki, Finland.
authors: Lars
authors: L
authors: Paulin
authors: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland.
authors: Kirsti
authors: K
authors: Lahti
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism*; D020562:Betaproteobacteria / Q000737:chemistry / Q000145:classification* / Q000235:genetics* / Q000378:metabolism; D001673:Biodegradation, Environmental; D000458:Cyanobacteria / Q000378:metabolism / Q000472:pathogenicity; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D005618:Fresh Water / Q000382:microbiology; D020459:Genes, rRNA; D019015:Geologic Sediments / Q000382:microbiology; D052998:Microcystins; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000378:metabolism*; D010641:Phenotype; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D052998:Microcystins; D010456:Peptides, Cyclic; D012336:RNA, Ribosomal, 16S; C063998:nodularin; C078588:microcystin