Abstract: In this study,previously screened highly laccase-yielding Phanerochaete chrysosporium as template,homologous cloning technology was employed to synthesize a full-length 1680 bp laccase gene. Alignment of nucleotide and amino acid sequences showed that the gene had high homology with fungal laccase gene,named as lac1680. Then the gene was connected to the pET24a vector,and transferred to the expression strain Escherichia coli BL21（DE3）. The whole cell lysates by the pre-expression of the recombinant strain was detected by SDS-PAGE,and 75 kD band was obtained,thus indicating that the gene expressed successfully. NI-NTA column was then used to purify the eluted lac1680 protein,and the purity was over 98%. Comparing the enzyme-producing activities between the gene engineering strain and wild P. chrysosporium strain in different culture time showed that the activity of engineering strain obviously improved by nearly 39% than the wild one.

Key words: Phanerochaete chrysosporium, laccase gene, heterogeneous expression, protein purification, enzyme activity