Effect of immobilization on the stability of wood-rooting fungi laccases

الملخص EN

Extracellular laccases produced by three different wood-rotting fungi, Cerrena unicolor.

Helerobasidion annosum, and Trametes versicolor.

were immobilized via covalent bonds formation on DEAE-Granocel 500.

CM-Granocel 500 and acrylic carriers.

Out of the tested carriers, only the DEAE-Granocel 500 was applicable, this was activated by divinyl sulfone appeared to be a suitable matrix for the expression of enzymatic activity.

It was only onelaccaseofallthe tested enzymes that was produced by Cerrena unicolor, which showed the best binding to the carrier, and a satisfactoty enzymatic activity.

The immobilized laccase exhibited the highest enzymatic activity at pH 5.2 and it was more resistant to thermal denaturizing than the native enzyme.

At 90°c.

it retained 75% of its activity as compared to the free enzyme.

It was also more sthle during storage at 4oC: after four months the immobilized laccase retained 98% of its initial activity.