Optimization of cellobiose dehydrogenase production by Schizophyllum commune and effect of the enzyme on kraft pulp bleaching by ligninases

The effects of various parameters on cellobiose dehydrogenase (CDH) product ion by Schizophyllum commune AS 5.391 were investigated. Among different ca rbon and nitrogen sources tested, dewaxed cotton powder and diammonium hydr ogen phosphate produced the highest titers of CDH. S. commune AS 5.391 prod uced CDH only when grown on cellulosic substrates but the lignin-related co mpounds veratryl alcohol and guaiacol had no effect on CDH production. The optimum pH for CDH production was 4.5. Addition of succinate and Tween 80 t o the medium significantly improved the enzyme yield. Optimized culture con ditions were obtained and the highest level of CDH was 150 U/l. CDH could f acilitate kraft pulp lignin degradation by ligninases. The influence of CDH on kraft pulp bleaching by ligninases was also studied. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.