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 8 h from 72 h. 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.