RESUMO
Cyclodextrin glycosyltransferase (CGTase) from Thermoanaerobacter sp. was covalently immobilized on glutaraldehyde-activated chitosan spheres and used in a packed bed reactor to investigate the continuous production of ß-cyclodextrin (ß-CD). The optimum temperatures were 75 °C and 85 °C at pH 6.0, respectively for free and immobilized CGTase, and the optimum pH (5.0) was the same for both at 60 °C. In the reactor, the effects of flow rate and substrate concentration in the ß-CD production were evaluated. The optimum substrate concentration was 4% (w/v), maximizing the ß-CD production (1.32 g/L) in a flow rate of 3 mL/min. In addition, the biocatalyst had good operational stability at 60 °C, maintaining 61% of its initial activity after 100 cycles of batch and 100% after 100 h of continuous use. These results suggest the possibility of using this immobilized biocatalyst in continuous production of CDs.