Heterologous production of a ligninolytic enzyme: Expression of the Phlebia radiata laccase gene in Trichoderma reesei

We have expressed a gene encoding the ligninolytic laccase enzyme of the white–rot fungus Phlebia radiata in the soft rot fungus Trichoderma reesei under the promoter of the major cellulase gene (cbh1). Constructions from the laccase cDNA or the chromosomal gene were equivalent in expression, yielding 20 mg/l of secreted active laccase in small–scale fermentations. The recombinant enzyme has a similar molecular weight, antigenic properties and specific activity as the Phlebia laccase and is analogous to the Phlebia enzyme in removing monomeric lignin–related compounds from residual lignin of the pulping process, thus demonstrating its potential for industrial applications.