LIGNINOLYTIC ENZYMES APPLIED TO KRAFT LIGNIN AND LIGNOSULFONATE UTILIZATION

LIGNIN, A COMPLEX ORGANIC POLYMER AND ONE OF THE EARTH'S MOST ABUNDANT MOLECULES, IS NOW A LOW-VALUE BY-PRODUCT OF WOOD PULP PROCESSING. THE MAJOR LIGNIN BY-PRODUCTS, KRAFT LIGNIN, AND LIGNOSULFONATES, COULD BE MORE USEFUL, HOWVERE, IF THEIR CHEMICAL STRUCTURE COULD BE SPECIFICALLY ALTERED. BY USING ENZYMES CAPABLE OF SPECIFICALLY DEGRADING AND MODIFYING LIGNIN, THESE BY-PRODUCTS WOULD FIND WIDER APPLICATIONS AS ADHESIVES, DISPERSANTS, AND FEEDSTOCK CHEMICALS. THESE LIGNIN DEGRADING AND MODIFYING (LDM) ENZYMES ARE PRODUCED UNDER SPECIFIED CULTURE CONDITIONS BY WHITE-ROT AND BROWN-ROT FUNGI AND BACTERIA. THE MAJOR ENZYMES PRODUCED BY THE WHITE-ROT FUNGUS PHANEROCHAETE CHRYSOSPORIUM HAVE BEEN PARTIALLY CHARACTERIZED. P. CHRYSOSPORIUM HAS BEEN SHOWN TO BE THE MOST POTENT LIGNINOLYTIC ORGANISM STUDIED. THIS PROGRAM IS TO FURTHER ISOLATE AND CHARACTERIZE LDM ENZYMES THAT CATALYZE SPECIFIC REACTIONS ON KRAFT LIGNIN AND LIGNOSULFONATES. THE REACTIONS IN- CLUDE A DEPOLYMERIZING ACTIVITY THAT CAN REDUCE THE SIZE OF THE LIGNIN SUBSTRATE AND A DECOLORIZING REAC- TION THAT ELIMINATES CHROMOPHORIC GROUPS FROM LIGNIN.