Biosynthesis of 2-O-α-D-glucopyranosyl-L-Ascorbic Acid from Maltose by Cyclodextrin Glucanotransferase from Bacillus sp

In this work 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) was synthesized by Cyclodextrin glucanotransferase (CGTase) from Bacillus sp. SK 13.002 with L-ascorbic acid (AA) as an acceptor and maltose as a glycosyl donor. AA-2G production was analyzed by HPLC and was confirmed by LC/MS results. The reaction parameters, such as pH (4.0-9.0), temperature (25-50°C), time (0-30 h), substrate ratios and enzyme concentration were optimized. The results showed that the optimum condition was pH 8.0 at 37°C for 24 h, 1:1 maltose to AA substrates mass ratio, and 200 U/mL of CGTase. Under these conditions, the production of AA-2G was 5.5 g/L, this result indicate that CGTase from Bacillus sp. SK 13.002 can effectively uses maltose as a glycosyl donor to produce AA-2G in high yield.