Fig. 4 indicates that, at the end of the 20 days of storage, the free
laccase and immobilized laccase retained about 22.4 1.8% and
82.7 0.9% of their initial activities, respectively. Similar findings
were observed by Huang et al. (2006), who reported that after
storage at 4 C for one month, the activity of Pycnoporus sanguineus
laccase immobilized on copper tetra-aminophthalocyanine-Fe3O4
nanoparticle composite was 85% of its initial activity, while that of
the free laccase was only 30%.