BIODEGRADATION OF MTBE AND OTHER GASOLINE OXYGENATES BY BUTANE-UTILIZING MICROORGANISMS

摘要

In this study, we present oxidation of MTBE (methyl tert-butyl ether) and other gasoline oxygenates by butane-grown microorganisms, ENV425 and a mixed culture. Our results indicate that butane-grown bacteria ENV425 and the mixed culture can cometabolically degrade MTBE and other gasoline oxygenates. The degradation of MTBE and other gasoline oxygenates was completely inhibited by acetylene and strongly influenced by the addition of n-butane. Two major products of MTBE degradation, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), were detected in the resting cell experiment while TBA was major product in the simultaneous degradation of n-butane and MTBE. The kinetics of products formation suggest that TBF production rapidly proceeds to TBA. Our results suggest that MTBE oxidation is initiated by butane-monooxygenase reactions, which lead to scission of the ether bond in this compound. Our findings also suggest a potential role for gaseous n-alkane-oxidizing bacteria in the remediation of MTBE contamination.