Application of cyclodextrinase in non‐complexant production of γ‐cyclodextrin

Abstract The production of γ‐cyclodextrin usually includes the utilization of organic complexants. However, the non‐complexant production of γ‐cyclodextrin is always being explored due to the defects of organic complexants. However, in non‐complexant production, the separation of γ‐cyclodextrin from α‐ and β‐cyclodextrin is still a challenge. Here, the selective hydrolysis ability of a cyclodextrinase designated PpCD (cyclodextrinase from Palaeococcus pacificus ) on α‐cyclodextrin, β‐cyclodextrin, and γ‐cyclodextrin was proved. The k cat /K m values of PpCD for α‐cyclodextrin and β‐cyclodextrin were roughly 12‐fold and 5‐fold higher than that of γ‐cyclodextrin. It was proved that PpCD had selective hydrolysis ability and its γ‐cyclodextrin purification performance was apparent on various simulated cyclodextrin mixtures with reported proportions derived from different CGTases. Besides, the hydrolysis temperature was optimized and it could be seen that 85°C was appropriate for the production of γ‐cyclodextrin. In addition, the production of γ‐cyclodextrin was achieved by using PpCD in the γ‐CGTase reaction products.