Production of Turanose by Cyclomaltodextrin Glucanotransferase from Bacillus stearothermophilus

Abstract

Cyclomaltodextrin glucanotransferase (EC 2.4.1.19, abbreviated as CGTase) from Bacillus stearothermophilus produced a series of transfer products from a mixture of cyclomaltohexaose and D-fructose. After digestion with glucoamylase, the resultant product contained turanose and trehalulose in addition to D-glucose and D-fructose. These results showed that CGTase transferred the glucose residue to the C3- and C1-hydroxy groups of fructopyranose. The optimum conditions on the turanose production from α-CD and D-fructose using CGTase were examined. The reaction mixture containing 30% of α-CD and 30% of D-fructose and 300 U/g of α-CD of CGTase from B. stearothermophilus was incubated at 60°C and pH 5.5 for 24 h and then treated with glucoamylase. Turanose was produced in a yield of about 45%.