Genetic characterization of the dibenzofuran-degrading Actinobacteria carrying the dbfA1A2 gene homologues isolated from activated sludge

Takashi Noumura, Hiroshi Habe, Jaka Widada, Jin Sung Chung, Takako Yoshida, Hideaki Nojiri, Toshio Omori

Research output: Contribution to journalArticle

11 Scopus citations


Thirteen dibenzofuran (DF)-utilizing bacteria carrying the DF terminal dioxygenase genes homologous to those of Terrabacter sp. strain DBF63 (dbfA1A2) were newly isolated from activated sludge samples. The amplified ribosomal DNA restriction analysis and the hybridization analyses showed that these strains were grouped into five genetically different types of bacteria. The sequence analyses of the 16S rRNA genes and the dbfA1A2 homologues from these five selected isolates revealed that the isolates belonged to the genus Rhodococcus, Terrabacter or Janibacter and that they shared 99-100% conserved dbfA1A2 homologues. We investigated the genetic organizations flanking the dbfA1A2 homologues and showed that the minimal conserved DNA region present in all five selected isolates consisted of an ≈9.0-kb region and that their outer regions became abruptly non-homologous. Among them, Rhodococcus sp. strain DFA3 possessed not only the 9.0-kb region but also the 6.2-kb region containing dbfA1A2 homologues. Sequencing of their border regions suggested that some genetic rearrangement might have occurred with insertion sequence-like elements. Also, within their conserved regions, some insertions or deletions were observed.

Original languageEnglish (US)
Pages (from-to)147-155
Number of pages9
JournalFEMS Microbiology Letters
Issue number1
StatePublished - Oct 1 2004



  • Actinobacteria
  • Dibenzofuran 4,4a-dioxygenase
  • Dibenzofuran degradation
  • Rhodococcus sp.
  • Terrabacter sp.

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics

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