MTBE and benzene biodegradation by a bacterial isolate via two independent monooxygenase-initiated pathways

A study on the biodegradation of MTBE and benzene was carried out using PM1 via two independent monooxygenase-initiated pathways. Mixtures of benzene and MTBE were readily degraded and substrate interactions in mixtures of these two compounds were distinctive. PM1 effectively utilized benzene for growth. MTBE-grown cells degraded up to 500 mg/L of MTBE with no apparent accumulation of tertiary butyl alcohol (TBA) MTBE- and TBA-grown cells did not consume oxygen with benzene or its breakdown products. While high oxygen uptake rates were observed for TBA with MTBE-grown cells, TBA-grown cells did not consume oxygen when exposed to MTBE suggesting that the monooxygenase enzyme systems induced by MTBE and TBA are potentially different. MTBE grown cells exhibited high oxygen uptake rates with TBF, TBA, 2-hydroxyisobutyric acid, 2-propanol and hydroxyacetone. With 2-methyl-2-hydropropanol and acetone, no oxygen uptake was observed, suggesting that either these two compounds are toxic to the cells at the tested concentrations or that the MTBE degradation pathway by PM1 differed slightly from previously proposed pathways. Studies were currently in progress to characterize the MTBE, TBA and benzene monooxygenases.

MTBE and benzene biodegradation by a bacterial isolate via two independent monooxygenase-initiated pathways Report