Heterologous expression of Pleurotus djamor laccase gene in Pichia pastoris and decolorization on dyes by recombinant laccase

Regarding the white rot fungus Pleurotus djamor RNA as the template,the complete CDS sequence of Pleurotus djamor Laccase Pd-lac1's gene was obtained by RT-PCR. The expression vector of Pichia pastori pPICZB-Pd-Lac1( recombinant expression vector) was constructed and was introduced into Pichia pastoris by electrotransformation. The PCR results showed that a part of positive transformants of the CDS sequence of Pd-Lac1 were integrated onto Pichia pastoris chromosomes. After liquid shake-flask culturing,Pastoris engineering strains with higher laccase expression were screened. The laccase activity was 54 U / L. Furthermore,the influence of recombinant laccase on the dye decolorization was studied.The result indicated that the decoloration rate of recombinant laccase to Alizarin Red( anthraquinone)could reach 52. 8%; the decoloration rates of Neutral Red( heterocyclic dye),methyl orange( azo dye)and Malachite Green( triphenylmethane) are lower than that of SN4 R,which are 14. 8%,14. 5% and0. 24%,respectively,showing that the decolorization efficiency of recombinant laccase to SN4 R had larger potential application,thereby having wider application prospect in the treatment of wastewater containing anthraquinone dyes.