Biodegradation of Methyl tert -Butyl Ether by a Bacterial Pure Culture

Abstract

ABSTRACT A bacterial strain, PM1, which is able to utilize methyl tert -butyl ether (MTBE) as its sole carbon and energy source, was isolated from a mixed microbial consortium in a compost biofilter capable of degrading MTBE. Initial linear rates of MTBE degradation by 2 × 10 6 cells ml −1 were 0.07, 1.17, and 3.56 μg ml −1 h −1 for initial concentrations of 5, 50, and 500 μg MTBE ml −1 , respectively. When incubated with 20 μg of uniformly labeled [ 14 C]MTBE ml −1 , strain PM1 converted 46% to 14 CO 2 and 19% to 14 C-labeled cells within 120 h. This yield is consistent with the measurement of protein accumulation at different MTBE concentrations from which was estimated a biomass yield of 0.18 mg of cells mg MTBE −1 . Strain PM1 was inoculated into sediment core material collected from a contaminated groundwater plume at Port Hueneme, California, in which there was no evidence of MTBE degradation. Strain PM1 readily degraded 20 μg of MTBE ml −1 added to the core material. The rate of MTBE removal increased with additional inputs of 20 μg of MTBE ml −1 . These results suggest that PM1 has potential for use in the remediation of MTBE-contaminated environments.