Lactulose production from lactose as a single substrate by a thermostable cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus

► Caldicellulosiruptor saccharolyticus cellobiose-2-epimerase produced lactulose. ► The enzyme synthesized first lactulose using the single substrate lactose. ► The enzyme produced also epilactose as another bifidus factor. ► Lactulose production by the enzyme is the highest among enzymatic syntheses.