Cellobiose quinone oxidoreductase from the white rot fungus Phanerochaete chrysosporium is produced by intracellular proteolysis of cellobiose dehydrogenase.

The fungus Phanerochaete chrysosporium was grown in a 10-l automatic fermenter using cellobiose as carbon source to monitor the induction of cellobiose dehydrogenase (CDH) and cellobiose quinone oxidoreductase (CBQ) enzymes, and to search for tentative cbq and cdh genes and their transcriptional products. After 24 h of induction, CDH was detected in the culture supernatant and a protein was recognized by a specific anti-CDH polyclonal antibody in the sonicated biomass. Northern blot experiments performed with several fungal RNA samples showed, after 24 h of induction, only one single species of an mRNA transcript corresponding in size to the cdh gene (2.