Aerobic Mineralization of MTBE and tert-Butyl Alcohol by Stream-Bed Sediment Microorganisms

Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert -butyl ether (MTBE) and tert -butyl alcohol (TBA). Up to 73% of [U- 14 C]-MTBE and 84% of [U- 14 C]-TBA were degraded to 14 CO 2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.