Phosphorylase coupling as a tool to convert cellobiose into amylose

This work aims to establish the enzymatic process to produce amylose from cellobiose. Incubation of cellobiose with cellobiose phosphorylase and α-glucan phosphorylase in the presence of maltotetraose and a catalytic amount of inorganic phosphate at 45 °C for 16 h resulted in the production of linear α-1,4-glucan with a 19.3% (w/v, against cellobiose weight) yield. The yield was successfully improved (32.4%) when mutarotase and glucose oxidase were added to remove glucose in the reaction mixture. The weight-average molecular weight of the product was precisely controlled from 42 to 720 kDa by changing the initial molar ratio of cellobiose to maltotetraose. The combined use of two different phosphorylases should be a useful tool in converting β-1,4-linked-polysaccharide into α-1,4-linked-polysaccharide.