Purification and characterization of a thermostable laccase with unique oxidative characteristics from Trametes hirsuta.

A laccase was purified from Trametes hirsuta. This laccase was classified as a "white" or "yellow" laccase. pH 2.4 was optimal for the oxidation of ABTS and pH 2.5 for DMP. DMP oxidation was optimal at 85 degrees C. The half-life of this laccase was 70 min at 75 degrees C, and 5 h at 65 degrees C. Non-phenolic dyes, such as Methyl Red, were oxidized by purified laccase without mediators. The enzyme was not inhibited by Cu(2+), Mn(2+), or EDTA. These are atypical laccase characteristics that make it a good candidate for theoretical and applied research.