Phosphorylase is a type of enzyme-producing sugar phosphates through the reversible phosphorolysis reactions of glycosides, which makes it an important starting enzyme in multi-enzyme systems for rare sugar biomanufacturing. To investigate its application in d-tagatose biosynthesis from maltodextrin using in vitro multi-enzyme cascade biosystem, the α-glucan phosphorylase (αGP; EC 2.4.1.1) from the thermophile D. turgidum DSM 6724 was prepared and characterized. It exhibited the specific activity of 30.28 U/mg at its optimal temperature of 70 °C. Thermostability results revealed that DituαGP could maintain more than 25% of initial activity for 4 h, even at 90 °C. The highest activity was observed at pH 5.5, and most divalent metal ions deactivated the enzyme. DituαGP exhibited great application potential in the multi-enzyme system that about 3.919 g/L of d-tagatose was produced from 150 g/L of maltodextrin within 36 h. DituαGP has played an important role in this biosystem and will also be applied in the synthesis of other rare sugars from maltodextrin.

磷酸化酶是一种通过糖苷的可逆磷酸解反应产生糖磷酸的酶，是稀有糖类生物制造多酶系统中的重要起始酶。为了研究其在使用体外多酶级联生物系统从麦芽糊精生物合成d-塔格糖中的应用，制备并表征了来自嗜热D. turgidum DSM 6724的 α-葡聚糖磷酸化酶 (αGP; EC 2.4.1.1) 。它在 70 °C 的最佳温度下表现出 30.28 U/mg 的比活性。热稳定性结果表明，地图即使在 90 °C 下，αGP 也可以在 4 小时内保持超过 25% 的初始活性。在 pH 5.5 时观察到最高活性，大多数二价金属离子使酶失活。Ditu αGP在多酶体系中显示出巨大的应用潜力，150 g/L的麦芽糊精在36小时内可产生约3.919 g/L的d-塔格糖。Ditu αGP 在这个生物系统中发挥了重要作用，也将用于从麦芽糊精合成其他稀有糖。