*** 9760044 Steffan This 6 month Phase I SBIR project involves the development of improved biocatalysts for destroying gasoline oxygenates such as methyl tert-butyl ether (MTBE), ethyl tert butyl ether (ETBE), and tert-amyl methyl ether (TAME). Oxygenates such as MTBE have been added to gasoline in the United States since the late 1970@, to replace lead and other toxic components. Currently, MTBE is second on the list of organic chemicals produced in the United States with greater than 24 billion pounds produced annually, and it has become one of the most common contaminants of urban groundwaters. Recent concern over groundwater contamination has led some states to reduce their allowable maximum levels of MTBE in groundwater to <100 ppb. The few studies that have addressed MTBE biodegradation have met with very limited success, thereby leading to the conclusion that MTBE is recalcitrant to biodegradation. Recent studies by Envirogen, however, have identified a class of microorganisms that can biodegrade MTBE, but can not use it as a growth substrate. The goal of the proposed work is to use modern molecular biological techniques to exploit knowledge gathered to date to develop an organisms that can grow on MTBE as a sole source of carbon and energy. The technology developed during this project will be applicable for destroying gasoline oxygenates in a variety of wastewaters including groundwater remediation and end-of-pipe treatment. Initially, the technology will be deployed in contained bioreactors, and eventually, upon deomonstrating the safety of the biocatalysts, in situ. More than 300,000 leaking gasoline storage tanks have been reported to regulatory agencies, and many of these sites contain MTBE-contaminated groundwater. The lack of alternative remediation alternatives for MTBE makes the proposed work commercially significant. ***
