title: Detection and sequencing of the microcystin LR-degrading gene, mlrA, from new bacteria isolated from Japanese lakes.
abstract: mlrA is the only microcystin-degrading gene detected in Sphingomonas sp. MJ-PV. The gene has an extremely rare nucleotide sequence and homologous genes have not yet been discovered in the DNA database. We discovered the existence of a gene homologous to mlrA in new microcystin-degrading bacteria, MD-1 and Y2. These strains possessed mlrA homologues, and the identities of the genes of MD-1 and Y2 with the corresponding MJ-PV exceeded 98% and 84%, respectively. On the other hand, the mlrA gene was not detected in laboratory strains of the closely related Sphingomonas spp. strains employing hemi-nested polymerase chain reaction detection using two primer sets. Although the microcystin-degrading bacteria were closely related strains, they did not cluster together as the same species. We can conclude that the mlrA gene is conserved in three different bacterial species, and it is unique to microcystin degraders but not to the genus Sphingomonas.
authors.affiliation: Bio-Eco Engineering Laboratory, National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki 305-8506, Japan. saitou.takeshi@nies.go.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saito
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Okano
authors.forename: Ho-Dong
authors.initials: HD
authors.lastname: Park
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Itayama
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Inamori
authors.forename: Brett A
authors.initials: BA
authors.lastname: Neilan
authors.forename: Brendan P
authors.initials: BP
authors.lastname: Burns
authors.forename: Norio
authors.initials: N
authors.lastname: Sugiura
mesh_terms: D007564:Japan; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020578:Sphingomonas / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D014871:Water Microbiology
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D012336:RNA, Ribosomal, 16S; C057862:cyanoginosin LR