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) production by Schizophyllum commune AS 5.391 were investigated. Among different carbon and nitrogen sources tested, dewaxed cotton powder and diammonium hydrogen phosphate produced the highest titers of CDH. S. commune AS 5.391 produced CDH only when grown on cellulosic substrates but the lignin-related compounds 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 to the medium significantly improved the enzyme yield. Optimized culture conditions were obtained and the highest level of CDH was 150 U/l. CDH could facilitate kraft pulp lignin degradation by ligninases. The influence of CDH on kraft pulp bleaching by ligninases was also studied.