Purification and Characterization of Pleurotus florida Laccase (L1) involved in the Remazol Brilliant Blue R (RBBR) Decoloration

Pleurotus florida produces two extracellular laccase (L1 and L2) isoenzymes and the L1 isoenzyme is dominantly involved in the dye decoloration process. L isoenzyme was successfully purified to 6.4 fold with a yield of 36% and had a specific activity of 52.6 U mg^-1 of protein. The purified laccase was monomeric with an apparent molecular mass of ≈54 kDa. The optimum pH and temperature of the LI isoenzyme was found to be around 5.5 and 50ºC, respectively. L1 isoenzyme showed a half life of 2 h at 60 ºC and at 4 h it retained around 25% residual activity. The kinetic parameters suggest that the order of affinity towards the tested substrates was syringaldazine > ABTS > DMP > guaiacol. Interestingly, L1 isoenzyme was not significantly inhibited by chloroform and benzene, whereas above 50% of laccase activity was inhibited by acetone, dimethyl sulfoxide and methanol.

کلیدواژه ها:

Decoloration ، Isoenzyme ، Laccase ، Pleurotus florida ، Purification ، White-rot fungi