Enzyme Properties of a Laccase Obtained from the Transcriptome of the Marine-Derived Fungus .

Only a few studies have examined how marine-derived fungi and their enzymes adapt to salinity and plant biomass degradation. This work concerns the production and characterisation of an oxidative enzyme identified from the transcriptome of marine-derived fungus . The laccase-encoding gene Lac2 from was cloned for heterologous expression in D15#26 for protein production in the extracellular medium of around 30 mg L. The extracellular recombinant enzyme Lac2 was successfully produced and purified in three steps protocol: ultrafiltration, anion-exchange chromatography, and size exclusion chromatography, with a final recovery yield of 24%. Lac2 was characterised by physicochemical properties, kinetic parameters, and ability to oxidise diverse phenolic substrates. We also studied its activity in the presence and absence of sea salt. The molecular mass of Lac2 was about 75 kDa, consistent with that of most ascomycete fungal laccases. With syringaldazine as substrate, Lac2 showed an optimal activity at pH 6 and retained nearly 100% of its activity when incubated at 50°C for 180 min. Lac2 exhibited more than 50% of its activity with 5% wt/vol of sea salt.