EFFECT OF ADDITION OF EXTRACELLULAR CULTURE FLUID ON LIGNINOLYTIC ENZYME FORMATION IN PHANEROCHAETE-CHRYSOSPORIUM

The influence of extracellular ligninolytic fluid addition on lignin p eroxidase (LIP), Mn-peroxidase (MNP) and glyoxal oxidase (GLOX) activi ty in free and immobilized (polyurethane foam) batch cultures of Phane rochaete chrysosporium was examined. Addition was carried out in sever al proportions during growth (day 0) and idiophasic phase (day 4). A d ecrease in the activity of added LIP was observed for both free pellet s and immobilized cultures. In both cases, a de novo LIP activity was slightly lower than in control cultures (without addition). MNP and GL OX activity was not significantly altered by the addition of ligninoly tic extracellular fluid. LIP and MNP isoenzymes were detected in diffe rent degrees, showing a typical behaviour of N-limited cultures of P. chrysosporium monitored at 409 nm. During late secondary metabolism in immobilized cultures, a second peak of ligninolytic activity was obta ined, for which the level of LIP activity was similar to the first one , but glyoxal oxidase activity was 3-fold higher. Isoenzyme profile fa r this second peak was typical of C-limitation, being H2 isoenzyme the predominant hemeprotein for all assays. Total protein profile (monito red at 280 nm) also showed another peak at 1.5-min elution volume, who se area was quite similar to the one obtained for H2. The proteins elu ted at 1.5 min were isolated and analyzed by SDS-electrophoresis, dete cting a band displaying proteolytic activity.