The gasoline additive methyl tert-butyl ether (MTBE) can contaminate groundwater and soil. In order to eliminate it, several methods are being developed, among which bioremediation - that is, the addition of microbial cultures that can degrade the compound - holds promise. Our laboratory has identified Achromobacter xylosoxidans MCM1/1 as an MTBE-degrading bacterial strain. It degrades 78% of this chemical in 5 days. In this study we also analyze the effects of MTBE on the biology of A. xylosoxidans MCM1/1 and compare its proteomic profile after incubation with MTBE with that of unchallenged bacteria. The 2D proteomic analysis shows that the following four proteins are induced by MTBE: 50S ribosomal protein LW, amino acid-binding periplasmic protein, ATP synthase and endoribonuclease L Characterizing the bacterial response to MTBE at the biochemical level identifies proteins that can be used by biocatalysts for soil and water bioremediation. (C) 2010 Elsevier Ltd. All rights reserved.