Time course of pyrene mineralization in the presence of various PAHs by Mycobacterium sp. strain S65 under non-induced (a) and induced (b) conditions. Mineralization of pyrene in the presence of unlabelled phenanthrene, fluoranthene, benz[a]anthracene, or benzo[a]pyrene, added to a concentration of 1 mg/l in each microcosm. The mineralization of a mixture of these PAHs and no unlabelled PAH substrates was also measured in this experiment. Mineralization of pyrene in the absence of co-substrates was used as a reference. Data points are the average of triplicate samples and error bars represent one standard deviation.