Coating of immobilised laccase for stability enhancement: A novel approach

We report on the coating of laccase immobilised on Al2O3 pellets by the sequential adsorption of oppositely charged polyelectrolytes for stability enhancement. The activity of the coated laccase was not only preserved but also increased in relation to the non-coated laccase. The decolouration of two synthetic dyes of different structure and ionisation, i.e. Methyl Green (MG) and Remazol Brilliant Blue R (RBBR) by the coated and the non-coated laccase was assessed. Both laccases led to similar decolouration levels but desorption from the pellets of the non-coated laccase was detected. This phenomenon did not occur in the coated laccase which showed the protective effect exerted by the layers.On the other hand, both the coated and the non-coated laccase retained its laccase activity after more than 28 cycles of ABTS reaction. It was observed that the retention of laccase activity increased with the number of layers. Also, laccase activity of both the coated and the non-coated laccase was retained after 5 days of RBBR decolouration, this effect being especially acute in the one-layer coated laccase. This would permit the reusability of laccase, which would mean a considerable economical advantage.

We report on the coating of laccase immobilised on Al2O3 pellets by the sequential adsorption of oppositely charged polyelectrolytes for stability enhancement. The activity of the coated laccase was not only preserved but also increased in relation to the non-coated laccase. This indicates the protective effect exerted by the layers against potential laccase-denaturising agents that could be present in the solution.Figure optionsDownload as PowerPoint slide