Mixed microbial cultures, naturally combined in two-member associations (169AC and 189AC), actively degraded the aromatic ester dimethylterephthalate as a single source of carbon and energy. The biodegrading activity of the associations and also of the pure culture combination was tested under polysubstrate conditions. When complementary substrates like methanol, xylol and ethylene glycol were added, the consisting of a bacterial and an actinomyces strains association 189, exhibited a higher activity. A biomass of this association was brought to freeze-drying and the lyophilizate saved biodegrading activity towards the studied substrate.