title: Isolation and characterization of monochloroacetic acid-degrading bacteria.
abstract: Five Burkholderia strains (CL-1, CL-2, CL-3, CL-4, and CL-5) capable of degrading monochloroacetic acid (MCA) were isolated from activated sludge or soil samples gathered from several parts of Japan. All five isolates were able to grow on MCA as the sole source of carbon and energy, and argentometry and gas chromatography-mass spectroscopy analyses showed that these five strains consumed MCA completely and released chloride ions stoichiometrically within 25 h. The five isolates also grew on monobromoacetic acid, monoiodoacetic acid, and L-2-monochloropropionic acid as sole sources of carbon and energy. In addition, the five isolates could not grow with DCA but dehalogenate single chlorine from DCA. Because PCR analyses revealed that all five isolates have an identical group II dehalogenase gene fragment and no group I deh gene, only strain CL-1 was analyzed further. The partial amino acid sequence of the group II dehalogenase of strain CL-1, named DehCL1, showed 74.6% and 65.2% identities to corresponding regions of the two MCA dehalogenases, DehCI from Pseudomonas sp. strain CBS-3 and Hdl IVa from Burkholderia cepacia strain MBA4, respectively. The secondary-structure motifs of the haloacid dehalogenase (HAD) superfamily and the amino acid residues involved in substrate binding, catalysis, and hydrophobic pocket formation were conserved in the partial amino acid sequence of DehCL1.
authors.affiliation: Biotechnology Research Center, The University of Tokyo, Tokyo, Japan.
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Horisaki
authors.forename: Eiko
authors.initials: E
authors.lastname: Yoshida
authors.forename: Kaori
authors.initials: K
authors.lastname: Sumiya
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Takemura
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yamane
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nojiri
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D004734:Energy Metabolism; D005798:Genes, Bacterial; D006867:Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019807:Iodoacetic Acid / Q000378:metabolism; D007564:Japan; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D012722:Sewage / Q000382:microbiology*; D012988:Soil Microbiology
chemical_list: D000085:Acetates; D012722:Sewage; C006972:chloroacetic acid; C016274:bromoacetate; D006867:Hydrolases; C034507:2-haloacid dehalogenase; D019807:Iodoacetic Acid