Purification and some properties of a phthalate ester hydrolyzing enzyme from Nocardia erythropolis

Summary A phthalate ester hydrolyzing enzyme has been purified from the culture broth of Nocardia erythropolis, a Gram-positive bacterium capable of degrading phthalate esters rapidly. The purified enzyme appeared homogeneous on polyacrylamide gel disc-electrophoresis, and its molecular weight was estimated to be about 15,000. The optimal pH and temperature were pH 8.6 and 42°C, respectively. The enzyme was stable in a pH range from 7.0 to 8.0 and below 30°C. The enzyme activity was stimulated by Ca²⁺ and taurocholate, but inhibited by several metals such as Hg²⁺. Most of the phthalate esters tested were hydrolyzed to phthalate and alcohols regardless of the type of side-chain. In addition, the enzyme rapidly hydrolyzed olive oil and tributyrin. This enzyme from N. erythropolis may be a novel type of lipase with broad substrate specificity.Microbial degradation of phthalate esters. Part X