Purification and characterisation of new laccase from Trametes polyzona WRF03

Graphical abstract

Highlights

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  Trametes polyzona WRF03 produced high yield of true laccase.

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  Trametes polyzona WRF03 laccase was relatively pH and temperature stable.

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  Fe ²⁺, sodium azide and sodium cyanide greatly inhibited laccase activity.

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  Trametes polyzona WRF03 laccase decolorised many classes of synthetic dyes.

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 Fe ²⁺ 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.