IMMOBILIZATION OF MANGANESE PEROXIDASE FROM LENTINULA EDODES AND ITS BIOCALALYTIC GENERATION OF MN-III-CHELATE AS A CHEMICAL OXIDANT OF CHLOROPHENOLS

Manganese peroxidase (MnP) purified from commercial cultures of Lentin ula edodes was covalently immobilized through its carboxyl groups usin g an azlactone-functional copolymer derivatized with ethylenediamine a nd 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) as a coupling reagent. The tethered enzyme was employed in a two-stage immobilized MnP bioreactor for catalytic generation of chelated Mn-III and subsequ ent oxidation of chlorophenols. Manganese peroxidase immobilized in th e enzyme reactor (reactor 1) produced Mn-III-chelate, which was pumped into another chemical reaction vessel (reactor 2) containing the orga nopollutant. Reactor 1-generated Mn-III-chelates oxidized 2,4-dichloro phenol and 2,4,6-trichlorophenol in reactor 2, demonstrating a two-sta ge enzyme and chemical system. H2O2 and oxalate chelator concentration s were varied to optimize the immobilized MnP's oxidation of Mn-II to Mn-III. Oxidation of 1.0 mM Mn-II to Mn-III was initially measured at 78% efficiency under optimized conditions. After 24 h of continuous op eration under optimized reaction conditions, the reactor still oxidize d 1.0 mM Mn-II to Mn-III with similar to 69% efficiency, corresponding to 88% of the initial MnP activity. (C) 1998 John Wiley & Sons, Inc.