ENHANCED PRODUCTION OF CELLOBIOSE DEHYDROGENASE IN CULTURES OF PHANEROCHAETE-CHRYSOSPORIUM SUPPLEMENTED WITH BOVINE CALF SERUM

The enzyme cellobiose dehydrogenase (CDH), produced by many wood-degra ding fungi has, in recent years, attracted considerable interest for i ts possible role in both cellulose and lignin degradation, To characte rize the enzyme better and to identify its role in the degradation of wood and wood components, it is desirable to produce it in higher amou nts. We report here that the addition of bovine calf serum to cellulos e-grown cultures of Phanerochaete chrysosporium enhances the productio n of certain enzymes, CDH in particular, The highest CDH production wa s obtained with 45 ml of serum/litre of medium added on day 3 or 4, Th e resultant CDH yield was approx. 700-800 units/litre, which was 3.5-4 times higher than that in cultures without serum, Serum addition also enhanced the production of beta-glucosidase, However, the impact on C DH production was the most dramatic, The enhanced enzyme production ca nnot be explained by increased rates of spore germination, simple nutr ient effects or cofactor effects. Fractionation of serum by Cohn's fra ctionation technique showed that the albumin (BSA) fraction had almost the same effect as whole serum, However, purified BSA had less effect than crude BSA (fraction V of Cohn's fractions), suggesting that an a dditional factor, probably a protease inhibitor in serum, also contrib uted to the effect of serum.