Figure 1: Synthesis of α-1,3-glucan.

(a) The source of GtfJ enzyme. IPTG is isopropyl β-D-1-thiogalactopyranoside, a protein inducer. (b) Scheme of enzymatic polymerization of α-1,3-glucan. (c) Pictures of enzymatic polymerization of α-1,3-glucan produced at 30 °C. The number indicates the polymerization day. (d) Effect of pH on GtfJ activity at 30 °C. The enzyme activity of GtfJ is defined as the amount of released fructose per minute (μmole/min, U) per one mL of GtfJ at the initial state of reaction.