PRODUCTION OF PHANEROCHAETE-CHRYSOSPORIUM LIGNIN PEROXIDASE

Lignin peroxidase (ligninase) of the white rot fungus Phanerochaete chrysosporium Burdsall was discovered in 1982 as a secondary metabolite. Today multiple isoenzymes are known, which are often collectively called as lignin peroxidase. Lignin peroxidase has been characterized as a veratryl alcohol oxidizing enzyme, but it is a relatively unspesific enzyme catalyzing a variety of reactions with hydrogen peroxide as the electron acceptor. P. chrysosporium ligninases are here glycoproteins. At least a number of isoenzymes are also phosphorylated. Two of the major isoenzymes have been crystallized. Until recently lignin peroxidase could only be produced in low yields in very small scale stationary cultures owing to shear sensitivity. Most strains produce the enzyme only after grown under nitrogen or carbon limitation, although strains producing lignin peroxidase under nutrient sufficiency have also been isolated. Activities over 2000 U dm-3 (as determined at 30-degrees to 37-degrees-C) have been reported in small scale Erlenmeyer cultures with the strain INA-12 grown on glycerol in the presence of soybean phospholipids under nitrogen sufficiency. In about 8 dm3 liquid volume pilot scale higher than 1000 U dm-3 (as determined at 23-degrees-C) have been obtained under agitation with immobilized P. chrysosporium strains ATCC 24725 or TKK 20512. Good results have been obtained for example with nylon web, polyurethane foam, sintered glass or silicon tubing as the carrier. The immobilized biocatalyst systems have also made large scale repeated batch and semicontinuous production possible. With nylon web as the carrier, lignin peroxidase production has recently been scaled up to 800 dm3 liquid volume semicontinuous industrial production process.