PRODUCTION AND CHARACTERIZATION OF LACCASE FROM BOTRYTIS-CINEREA-61-34

An isolate of Botrytis cinerea (strain 61-34) constitutively expresses substantial amounts of extracellular laccase on a defined growth medi um, The enzyme has been purified to homogeneity by a facile operationa l sequence, the last stage of which involves hydrophobic interaction c hromatography. By these means, over 80 mg of laccase liter(-1) can be obtained from aerated fermenter reaction broths, The enzyme, with an e stimated M(r) of 74,000 and pI of 4.0, is a monomeric glycoprotein con taining 49% carbohydrate predominantly as hexose. With 2,6-dimethoxyph enol, it exhibits a pH optimum of 3.5 and a temperature optimum of 60 degrees C, and its K-m is 100 mu M. The purified enzyme with this subs trate has a specific activity of 9.1 mkat mg of protein(-1). Taken tog ether with a broad substrate range and its stability in 4% sodium dode cyl sulfate or 2 M urea solutions, several biotechnology transfers are suggested.