Effects of immobilization, pH and reaction time in the modulation of α-, β- or γ-cyclodextrins production by cyclodextrin glycosyltransferase: Batch and continuous process.

This study reports the immobilization of a β-CGTase on glutaraldehyde pre-activated silica and its use to production of cyclodextrins in batch and continuous reactions. We were able to modulate the cyclodextrin production (α-, β- and γ-CD) by immobilization and changing the reaction conditions. In batch reactions, the immobilized enzyme reached to maximum productions of 4.9mgmL-1 of α-CD, 3.6mgmL-1 of β-CD and 3.5mgmL-1 of γ-CD at different conditions of temperature, pH and reaction time. In continuous reactor, varying the residence time and pH it was possible to produce at pH 4.0 and 141min of residence time preferentially γ-CD (0.75 and 3.36mgmL-1 of α- and γ-CD, respectively), or at pH 8.0 and 4.81min α- and β-CDs (3.44 and 3.51mgmL-1 ).