Forty-five microbial cultures have been isolated from a chemically polluted region, using dimethylterephthalate (DMT) as a sole carbon and energy source. They have been subjected to adaptive selection in order to increase their biodegradative potential. The gradual increase of the xenobiotic substrate concentration from 2.5 to 25 mM induced adaptive changes in the tested strains. 20% of the studied strains showed a high biodegradative activity towards DMT and the best adaptation was expressed by the soil microorganisms.