Representative log10-transformed substrate depletion profiles for benzo[a]pyrene (BAP), pyrene (PYR), and phenanthrene (PHEN), anthracene (ANTH), fluorene (FLU), and naphthalene (NAPH). All data are from experiments which yielded the median rate of activity determined for each compound. To facilitate comparisons, concentration data from active (closed circles) and heat-denatured (open circles) cell suspensions were normalized to the starting concentration.