Purification and characterisation of new laccase from Trametes polyzona WRF03

Abstract

The molecular screening for laccase specific gene sequences in Trametes polyzona WRF03 (TpWRF03) using designed oligonucleotide primers analogous to the conserved sequences on the copper-binding regions of known laccases showed positive amplification with an amplicon size corresponding to 1500 bp. The purified TpWRF03 laccase (TpL) is a monomer with a molecular weight corresponding to 66 kDa. The enzyme had an optimal pH of 4.5 and temperature of 55 °C. TpL was most stable within pH of 5.5–6.5 and at a temperature range of 40–50 °C. Sodium azide, sodium cyanide and Fe2+ greatly inhibited the enzyme activity. TpL showed more than 50 % decolourisation efficiency on coomassie brilliant blue (72.35 %) and malachite green (57.84 %) but displayed low decolourisation efficiency towards Azure B (1.78 %) and methylene blue (0.38 %). The results showed that TpWRF03 produces high-yield of true laccase with robust properties for biotechnological applications.

Keywords

• Laccase
• ABTS
• Trametes polyzona WRF03
• Oligonucleotide primers
• Dye decolourisation