Recombinant expression of bacterial lignin-active laccases and peroxidase in Streptomyces lividans

A number of laccases and dye-decolorizing peroxidases from bacteria belonging to the genera Pseudomonas, Bacillus, Rhodococcus and Streptomyces have been shown to be active on lignin. We constructed bacterial strains for the production of different oxidative activities also in secretory form, as most described bacterial “small laccases” and a number of peroxidases show features consistent with an export through the Tat-secretory pathway. We chose the small laccases from Streptomyces coelicolor, Streptomyces viridosporus and Amycolatopsis sp. 75iv2, as well as the peroxidase DyP2 from Amycolatopsis sp. 75iv2 and established their production in Streptomyces lividans TK24. The peroxidase (which lacks a native signal peptide) can be produced intracellularly as well as secretorily using a heterologous signal peptide, the three laccases can be secreted with their native signal peptides.