Azoreductase activity in the hard clam, Mercenaria mercenaria (L.)

The ability of the hard clam Mercenaria mercenaria (L.) to metabolize compounds containing an azo linkage has been investigated. The hepatopancreas has azoreductase activity as evidenced by the reduction of 1,2-dimethyl-4-(p-carboxyphenylazo)-5-hydroxybenzene. This activity was higher at 37°C than at 22°C and the pH optimum was 8.0. The reaction was stimulated by the addition of flavin mononucleotide and inhibited by air. Activity was found in both the 105,000 g soluble and the microsomal fractions of the hepatopancreas.