A cyclodextrin glycosyltransferase (CGTase) from an alkaliphilic Bacillus sp. strain, isolated from Cuban soil, was purified with Sephadex G-50 with a yield of 66.5%. The CGTase was stable over a very wide pH range, 6.0–10, at 25°C and was most active at pH 7.5. The enzyme exhibited an optimum temperature of 60°C and was stable to 50°C for at least 8 h. The T 50 value – defined as the temperature at which 50% of the initial activity was retained–was 63°C in this enzyme. The influence of substrate or product concentration on the initial rate of CD production was studied, and the kinetic parameters were determined. The analysis of kinetic parameters K m and V max was obtained by the action of CGTase on the starch of corn with respect to β-CD, and the values were 4.1 g/L and 5.2 μM β-CD/min ml, respectively. The purified CGTase from Bacillus sp. could be used for an efficient cyclodextrin (CD) production which is the significant yield of γ- CDs.
|Keywords:||Cyclodextrin glycosyltransferase, Bacillus.sp, Cuba soil, γ-cyclodextrins|