Immobilization of manganese peroxidase from Lentinula edodes and its biocatalytic generation of MnIII-chelate as a chemical oxidant of chlorophenols.
Manganese peroxidase (MnP) purified from commercial cultures of Lentinula edodes was covalently immobilized through its carboxyl groups using an azlactone-functional copolymer derivatized with ethylenediamine and 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 MnIII and subsequent oxidation of chlorophenols. Manganese peroxidase immobilized in the enzyme reactor (reactor 1) produced MnIII-chelate, which was pumped into another chemical reaction vessel (reactor 2) containing the organopollutant. Reactor 1-generated MnIII-chelates oxidized 2,4-dichlorophenol and 2,4, 6-trichlorophenol in reactor 2, demonstrating a two-stage enzyme and chemical system. H2O2 and oxalate chelator concentrations were varied to optimize the immobilized MnP's oxidation of MnII to MnIII. Oxidation of 1.0 mM MnII to MnIII was initially measured at 78% efficiency under optimized conditions. After 24 h of continuous operation under optimized reaction conditions, the reactor still oxidized 1.0 mM MnII to MnIII with approximately 69% efficiency, corresponding to 88% of the initial MnP activity.
Grabski
A C
AC
Novagen, 601 Science Drive, Madison, Wisconsin 53711, USA. tony.grabski@novagen.com
Grimek
H J
HJ
Burgess
R R
RR
D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods; D002384:Catalysis; D002614:Chelating Agents; D002733:Chlorophenols; D004800:Enzymes, Immobilized / Q000378:metabolism*; D007202:Indicators and Reagents; D020074:Lentinula / Q000201:enzymology*; D008345:Manganese; D016877:Oxidants; D010544:Peroxidases / Q000378:metabolism*; D011804:Quinolines
D002614:Chelating Agents; D002733:Chlorophenols; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D016877:Oxidants; D011804:Quinolines; D008345:Manganese; C000470:EEDQ; D010544:Peroxidases; C051129:manganese peroxidase