title: Diversity of catechol 2,3-dioxygenase genes of bacteria responding to dissolved organic matter derived from different sources in a eutrophic lake.
abstract: Catechol 2,3-dioxygenase (C23O) is an extradiol dioxygenase that plays an important role in degrading aromatic compounds such as those found at polluted sites. However, little is known about the diversity of C23O genes in unpolluted environments. In such environments, various factors, including the quality and quantity of dissolved organic matter (DOM), could influence the composition and behaviour of bacterial community possessing C230 genes. We investigated C23O genes in bacteria responding to DOM from various sources in a eutrophic lake by PCR and cloning. Six microcosms filled with lake water containing indigenous bacteria and DOM from different sources were incubated for 10 days. After 1 or 2 days of incubation, C23O genes were detected in the microcosms enriched with DOM recovered from inflow river water and humus from reed grass. The sequences were very diverse but had features conserved in extradiol dioxygenases. The clone libraries generated on day 2 showed distinctive compositions among microcosms, indicating that bacteria possessing a variety of C23O genes responded differently to DOM from different sources. After 10 days of incubation, C23O genes in a previously unidentified gene cluster, 'Cluster X', became dominant in the libraries.
authors.affiliation: Department of Urban Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan. kasuga@env.t.u-tokyo.ac.jp
authors.forename: Ikuro
authors.initials: I
authors.lastname: Kasuga
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Nakajima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Furumai
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D050557:Catechol 2,3-Dioxygenase / Q000235:genetics*; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D014644:Genetic Variation / Q000187:drug effects; D005843:Geography; D007564:Japan; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000737:chemistry* / Q000494:pharmacology; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D014871:Water Microbiology
chemical_list: D009930:Organic Chemicals; D050557:Catechol 2,3-Dioxygenase