High-efficiency production of γ-cyclodextrin using β-cyclodextrin as the donor raw material by cyclodextrin opening reactions using recombinant cyclodextrin glycosyltransferase.

In comparison with natural α- and β-cyclodextrin (CD), γ-CD has attracted much attention due to their large hydrophobic cavities, high water solubility, and bioavailability. However, the production of γ-CD is still rather expensive and time-consuming. To overcome the high cost and long induction time, pUC119 was selected as the gene expression vector, and the recombinant enzyme production time was reduced to 8h from 72h. Furthermore, for the first time, we have successfully produced γ-CD using β-CD by cyclodextrin opening reactions through the recombinant CGTase in the presence of maltose. The kinetic mechanism of the coupling reaction was investigated. Moreover, the production of γ-CD could be affected by several key parameters, such as solvent type, reaction time, pH, and temperature. A maximum γ-CD yield of 32.9% was achieved by recombinant CGTase in the presence of 5-cyclohexadecen-1-one. This could be a promising method for the industrial production of γ-CD.