The gasoline additive methyl tert-butyl ether (MTBE) is the second most prevalent contaminant in groundwater in the United States, and there are currently no economical technologies for its removal from the water supply. Envirogen scientists have recently isolated a novel bacterium (ENV 735) that utilizes MTBE as a growth substrate. This is only the second report of a pure culture that is capable of growing on MTBE. The objective of this Phase I Proposal is to evaluate the potential application of strain ENV 735 for in situ bioremediation of MTBE. Aquifer microcosms will be used to measure the kinetics of MTBE degradation by ENV 735 under different microbiological and geochemical conditions. In addition, the pathway of MTBE degradation by ENV 735 will be studied, and experiments will be conducted to determine whether the metabolic capacity to degrade MTBE is shared among other bacteria of the same class as ENV 735. The data from this study will be used to assess the feasibility of using ENV 735 and similar microorganisms for in situ remediation of MTBE in contaminated aquifers. The commercial potential for a remediation technology that allows rapid, efficient, and cost effective destruction of MTBE in groundwater is tremendous. This potential derives from the following factors: (1) MTBE is the second most prevalent groundwater contaminant in the United States (e.g., 79 % of wells in urban Denver were recently found to be contaminated); (2) traditional technologies are ineffective at removing this contaminant from groundwater, and (3) MTBE has been shown to cause cancer in laboratory animals, thus regulatory concern is high. Based on these factors, ENVIROGEN analysts expect MTBE to be one of the most active remediation markets over the next decade.
