Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

Microorganisms indigenous to the stream-bed sediments at two gasoline-conta minated groundwater sites demonstrated significant mineralization of the fu el oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-C-14]-MTBE and 84% of [U-C-14]-TBA were degraded to (CO2)- C-14 under mixed aerobic/anaerobic conditions. No significant mineralizatio n was observed under strictly anaerobic conditions. The results indicate th at, under the mixed aerobic/anaerobic conditions characteristic of stream-b ed sediments, microbial processes may provide a significant environmental s ink for MTBE and TBA delivered to surface water bodies by contaminated grou ndwater or by other sources.