Kinetic characteristics of β-cyclodextrin production by cyclodextrin glucanotransferase from Bacillus sp. DSM 2523

Cyclodextrins (CD) are synthesized by bacterial cyclodextrin glucanotransferase (CGTase) and is widely used in food, pharmaceutical, cosmetic, and agricultural industries. In this study, the kinetic characteristics of β-cyclodextrin production by the CGTase from Bacillus sp. DSM 2523 was studied. Considering the initial production rate of β-cyclodextrin using different concentrations of the soluble starch (uo to 5 %w/v soluble starch), the kinetic parameters of Vmax and Km of β-CD production was determined by fitting the data of the initial production rates and substrate concentrations to the Lineweaver-Burk plot. The values of Vmax and Km were 16.1 μM/min and 0.25 %w/v (or 2.5 mg/ml), respectively. The Km parameter is correlated to the affinity of the enzyme for its substrate and it depends on the sources of the enzyme and substrate. Comparing the same source of starch, the Km value of CGTase in this study for soluble starch was much lower than that of CGTase from other Bacillus sp. This study provided the necessary kinetic information that may be useful to define the most suitable condition for industrialized production of β-cyclodextrin with the high yield and productivity