Borate enhances the production of lactulose from lactose by cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus

Cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus was used in the presence of borate to increase the production of lactulose from lactose. Maximum production of lactulose occurred using a 1:1 M ratio of borate–lactose. Under this condition, the enzyme produced 614 g l−1 lactulose from 700 g l−1 lactose after incubation at pH 7.5 and 80 °C for 3 h, with a conversion yield of 88% and a productivity of 205 g l−1 h−1. The yield and productivity of lactulose production obtained in the present study are among the highest achieved through chemical or biological synthesis.