Expression and characterization of LacMP, a novel fungal laccase of Moniliophthora perniciosa FA553.

To characterize a putative laccase gene, LacMP, of Moniliophthora perniciosa FA553 that had been screened using a genome mining approach, then cloned and expressed in Pichia pastoris. The purified recombinant LacMP was ~57 kDa with a maximum laccase activity of 232 U/l. The optimal pH for oxidation reactions with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), syringaldazine, guaiacol and 2,6-dimethoxyphenol, were 6, 7.5, 6.5, and 6.5, respectively. The laccase activity was optimal at 60, 45, 45, and 55 °C for the four respective substrates. LacMP was stable at pH 6-8 and <30 °C. Li(+), K(+), Co(2+), Ni(2+), Mn(2+), and Mg(2+) at 1 mM had no obvious effect on its activity. Given that LacMP has optimal activity under neutral and alkaline oxidation reaction conditions, it could be a potential candidate for industrial biocatalytic applications.