Heterologous expression and characterization of a laccase from Laccaria bicolor in Pichia pastoris and Arabidopsis thaliana.

Laccases can oxidize a variety of phenolic and non-phenolic substrates including synthetic dyes. In this research, a laccase gene Lcc9 from Laccaria bicolor was chemically synthesized and optimized to heterogeneous expression in Pichia pastoris and Arabidopsis thaliana. The properties of recombinant laccase expressed by P. pastoris were investigated. The laccase activity was optimal at 3.6 pH and 40 °C. It exhibited Km and Vmax values of 0.565 mmol l-1 and 1.51 μmol l-1 min-1 for ABTS respectively. As compared with untransformed control plants, the laccase activity in crude extracts of transgenic lines exhibited a 5.4 to 12.4-fold increased. Both laccases expressed in transgenic P. pastoris or A. thaliana could decolorize crystal violet. These results indicated that L. bicolor laccase gene may be transgenically exploited in fungi or plants for dye decolorization.