Expression, secretion and functional characterization of three laccases in E. coli

Endocrine Disrupting Chemicals (EDCs) are a group of molecules that can influence hormonal balance, causing disturbance of the reproductive system and other health problems. Despite the efforts to eliminate EDC in the environment, all current approaches are inefficient and expensive. In previous research, studies revealed that laccase-producing microorganisms may be a potential candidate for EDC degradation, as laccases have been found to be able to degrade many kinds of EDCs effectively and steadily. Here, we created two recombinant laccases, each fused with secretion peptide, Novel Signal Peptide 4 (NSP4), and expressed them in Escherichia coli (E. coli, BL21), together with one laccase without secretion peptide. We first optimized the culture condition of expressing these laccases. Then, we test the activity of the recombinant laccases of decolorizing of a synthetic dye, indigo carmine. Finally, we confirmed the secreted can degrade one of the EDCs, β-estradiol, showing the potential of using the laccase secretion system to degrade toxic compounds.