Purification and characteristics of an inducible by polycyclic aromatic hydrocarbons NADP(+)-dependent naphthalenediol dehydrogenase (NDD) in Mucor circinelloides YR-1.

We detected NADP(+)-dependent dihydrodiol dehydrogenase (DD) activity in a cell-free extract from Mucor circinelloides YR-1, after high-speed centrifugation. We analyzed the enzymatic activity in the cytosolic fraction by zymograms, as described previously, and eight different DD activity bands were revealed. Five constitutive DD activities (DD1-5) were present when glucose was used as carbon source and three inducible activities (NDD, PDD1 and PDD2) when aromatic hydrocarbon compounds were used.

Analysis of glycerol dehydrogenase activities present in Mucor circinelloides YR-1.

Two inducible NADP(+)-dependent glycerol dehydrogenase (GlcDH) activities were identified in Mucor circinelloides strain YR-1. One of these, denoted iGlcDH2, was specifically induced by n-decanol when it was used as sole carbon source in the culture medium, and the second, denoted iGlcDH1, was induced by alcohols and aliphatic or aromatic hydrocarbons when glycerol was used as the only substrate. iGlcDH2 was found to have a much broader substrate specificity than iGlcDH1, with a low activity as an ethanol dehydrogenase with NAD(+) or NADP(+) as cofactor.