Degradation of PCB congeners by RHA1 (black bars), by the bphA1 mutant, HDA1 (gray bars), and by the etbA1 ebdA1 double knockout, HDBT1 (white bars). Solution A consisted of five mainly ortho-substituted PCB congeners, 2,2′-dichlorobiphenyl, 2,3-dichlorobiphenyl, 2,5,2′-trichlorobiphenyl, 2,5,2′,5′-tetrachlorobiphenyl, and 2,4,5,2′,5′-pentachlorobiphenyl. Solution B consisted of five mainly para-substituted PCB congeners, 4,4′-dichlorobiphenyl, 2,4,2′,4′-tetrachlorobiphenyl, 2,4,3′,4′-tetrachlorobiphenyl, 3,4,3′,4′-tetrachlorobiphenyl, and 2,4,5,2′,4′,5′-hexachlorobiphenyl. Each value is the mean of triplicate independent experiments, with the standard deviation indicated by error bars.