Molecular characterization of dioxygenases from polycyclic aromatic hydrocarbon-degrading Mycobacterium spp.
Article first published online: 9 JAN 2006
FEMS Microbiology Letters
Volume 223, Issue 2, pages 177–183, June 2003
How to Cite
Brezna, B., Khan, A. A. and Cerniglia, C. E. (2003), Molecular characterization of dioxygenases from polycyclic aromatic hydrocarbon-degrading Mycobacterium spp. FEMS Microbiology Letters, 223: 177–183. doi: 10.1016/S0378-1097(03)00328-8
- Issue published online: 9 JAN 2006
- Article first published online: 9 JAN 2006
- Received 17 April 2003, Accepted 17 April 2003
- Polycyclic aromatic hydrocarbon degradation;
- DNA sequence;
Polycyclic aromatic hydrocarbon (PAH)-degrading genes nidA and nidB that encode the α and β subunits of the aromatic ring-hydroxylating dioxygenase have been cloned and sequenced from Mycobacterium vanbaalenii PYR-1 [Khan et al., Appl. Environ Microbiol. 67 (2001) 3577–3585]. In this study, the presence of nidA and nidB in 12 other Mycobacterium or Rhodococcus strains was investigated. Initially, all strains were screened for their ability to degrade PAHs by a spray plate method, and for the presence of the dioxygenase Rieske center region by polymerase chain reaction (PCR). Only Mycobacterium sp. PAH 2.135 (RJGII-135), M. flavescens PYR-GCK (ATCC 700033), M. gilvum BB1 (DSM 9487) and M. frederiksbergense FAn9T (DSM 44346), all previously known PAH degraders, were positive in both tests. From the three positive strains, complete open reading frames of the nidA and nidB genes were amplified by PCR, using primers designed according to the known nidA and nidB sequences from PYR-1, cloned in the pBAD/Thio-TOPO vector and sequenced. The sequences showed >98% identity with the M. vanbaalenii PYR-1 nidA and nidB genes. Southern DNA–DNA hybridization using nidA and nidB probes from PYR-1 revealed that there is more than one copy of nidA and nidB genes in the strains PYR-1, BB1, PYR-GCK and FAn9T. However, only one copy of each gene was observed in PAH2.135.