Biodegradation of fuel oxygenates and their effect on the expression of a newly identified cytochrome P450 gene in Achromobacter xylosoxidans MCM2/2/1

• Achromobacter xylosoxidans MCM2/2/1 was reported to degrade Ethyl tert butyl ether (ETBE) and Methyl tert butyl ether (MTBE).
• Presence of putative cytochrome P450 was identified in A. xylosoxidans MCM2/2/1 through PCR.
• Expression of the putative cytochrome P450 gene was altered in the presence of MTBE and TBA.
• Full length cytochrome P450 gene was identified.

Achromobacter xylosoxidans MCM2/2/1 was enriched and isolated from gasoline-contaminated soil and was found to degrade ethyl tert-butyl ether (ETBE) and methyl tert-butyl ether (MTBE) by 41.48% and 34.15%, respectively, in 6 days. Furthermore, the effect of MTBE and TBA on the expression of cytochrome P450 (CYP) of A. xylosoxidans MCM2/2/1 was examined. The presence of the CYP gene in this organism was first confirmed by amplification of a putative 350 bp CYP gene fragment followed by identification of the entire gene by genome walking and DNA-sequencing. The identified CYP gene of A. xylosoxidans MCM2/2/1 shares a high similarity of about 88% with the thcB gene of A. xylosoxidans A8. Gene expression studies have shown that the CYP gene is expressed in A. xylosoxidans MCM2/2/1; however, the expression of this gene was altered at different concentrations of MTBE.