The reaction conditions for γ-CD production by a purified CGTase from Brevibacterium sp. No. 9605 were investigated. The optimum pH and temperature for γ-CD formation were 7.0 and 50°C, respectively. The addition of calcium ion increased heat stability of the CGTase and the CDs formation was affected by the concentration of calcium ion. In the presence of ethanol, the yield of γ-CD from soluble starch was increased.
