Approaches for yield increase of [beta]-cyclodextrin formed by cyclodextrin glucanotransferase from Bacillus megaterium

Two methods for increasing β-cyclodextrin yield, achieved with cyclodextrin glucanotransferase from Bacillus megaterium were investigated. A membrane process was performed, allowing a reuse of the enzyme. A process for simultaneous production and isolation of β-cyclodextrin in the presence of complexing agents was conducted. The β-cyclodextrin yield was increased twofold, when the product was precipitated with trichloroethylene or toluene. A change in the product selectivity of cyclodextrin glucanotransferase occurred, resulting in an increase in the relative amount of β-cyclodextrin up to 90% of all cyclodextrins formed. Yield increase was due to the removal of product inhibition and the coupling activity of the enzyme, which limited the full conversion of starch. The isolated cyclodextrin products contained 75-79% β-cyclodextrin, and 4-6% each of α-, and γ-cyclodextrins. [PUBLICATION ABSTRACT]