Isolation and characterization of a rhodococcus species strain able to grow on ortho- and para-xylene

J Microbiol. 2005 Aug;43(4):325-30.


Rhodococcus sp. strain YU6 was isolated from soil for the ability to grow on o-xylene as the sole carbon and energy source. Unlike most other o-xylene-degrading bacteria, YU6 is able to grow on p-xylene. Numerous growth substrate range experiments, in addition to the ring-cleavage enzyme assay data, suggest that YU6 initially metabolizes o- and p-xylene by direct aromatic ring oxidation. This leads to the formation of dimethylcatechols, which was further degraded largely through meta-cleavage pathway. The gene encoding meta-cleavage dioxygenase enzyme was PCR cloned from genomic YU6 DNA using previously known gene sequence data from the o-xylene-degrading Rhodococcus sp. strain DK17. Subsequent sequencing of the 918-bp PCR product revealed a 98% identity to the gene, encoding methylcatechol 2,3-dioxygenase from DK17. PFGE analysis followed by Southern hybridization with the catechol 2,3-dioxygenase gene demonstrated that the gene is located on an approximately 560-kb megaplasmid, designated pJYJ1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Southern
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Dioxygenases / biosynthesis
  • Dioxygenases / genetics
  • Electrophoresis, Gel, Pulsed-Field
  • Enzyme Induction
  • Genome, Bacterial
  • Polymerase Chain Reaction
  • Rhodococcus / enzymology
  • Rhodococcus / genetics
  • Rhodococcus / growth & development*
  • Rhodococcus / isolation & purification*
  • Sequence Analysis, DNA
  • Soil Microbiology*
  • Xylenes / metabolism*


  • DNA, Bacterial
  • Xylenes
  • 4-xylene
  • Dioxygenases
  • 2-xylene