The application of magnetically modified bacterial cellulose for immobilization of laccase.

The usefulness of bacterial cellulose (BC), obtained from the cultures of Komagataeibacter xylinus exposed to rotating magnetic field (RMF), as a carrier for laccase immobilization was investigated in this study. It was found that the highest yield of laccase immobilization (>70%) was achieved in pH of 4.0 and this value was optimal in the case of both types of cellulose carriers applied. The pH equals 4.0 was also the optimal one with regard to immobilized enzymes' activity, while in case of free laccase, optimal pH value was 3.0. Process of immobilization had an impact on enzyme's optimal temperatures: while free laccase and laccase bound to RMF-unexposed cellulose was the most effective at 60°C, optimal activity of enzyme immobilized on RMF-exposed carrier was reached at 70°C. Laccase immobilized on both type of carriers had also better thermal stability at 70°C compared to free laccase. After 8 cycles of use, laccase immobilized on RMF-exposed BC remained more active than laccase immobilized on RMF-unexposed BC (65% vs. 50% of initial activity, respectively). Our results indicate that RMF-modified BC may be successfully used as a carrier for the laccase immobilization.