The optimum temperature for activity was also increased afterenzyme immobilization (Fig. 2A). The free enzyme presented thehighest activity at 50◦C; however, the immobilized enzyme pre-sented maximum activity at 60◦C, maintaining a high activity evenup to 80◦C (at this temperature the free enzyme was almost inac-tive). Fig. 2B shows that the enzyme was actually more stable thanthe free enzyme at 60◦C, and that may be the explanation for thisimproved features found in the immobilized enzyme. After 12 h ofincubation, the immobilized derivative retained about 60% activity,whilst the free form retained just 30% activity (Fig. 2B). The timeneeded to reach 50% of residual activity was about 3 h for the freeenzyme and about 19 h for immobilized preparation. Rigidificationof the enzyme structure via multipoint attachment and reductionof dissociation problems via multi-subunit immobilization are thelikeliest explanations, for these good results.