解脂耶氏酵母表面展示β-淀粉酶与α-葡萄糖转苷酶及一步法由淀粉合成低聚异麦芽糖

One step production of isomalto-oligosaccharides by engineered Yarrowia lipolytica yeast co-displayed β-amylase and α-transglucosidase

摘要:

低聚异麦芽糖 (IMO) 所具有的良好理化性质和生理功能，使得其在食品、医药、饲料、化妆品等领域得到广泛应用。但目前工业上采用多酶协同法由淀粉合成低聚异麦芽糖，步骤繁琐、成本较高。因此开发出更加经济简便的方法生产低聚异麦芽糖具有重要的应用价值。通过将β-淀粉酶 (βa) 和耐热α-葡萄糖转苷酶 (GT) 以不同的方式进行融合，并利用表面展示系统固定在食品安全微生物解脂耶氏酵母细胞表面，实现自我表达与固定。筛选得到高产菌株Yβa-GT29。大量培养获得细胞，转化液化的淀粉可实现一步法合成IMO，50 ℃转化20 h即可得到纯度为75.3%的低聚异麦芽糖，方便了低聚异麦芽糖的生产。

Abstract:

Isomalto-oligosaccharides (IMO) have good physiochemical properties and excellent physiological functions to make it widely used in food, medicine, feed, cosmetics and other industries. However, the procedures for industrial production of IMO are complicated. Therefore, it is necessary to develop an economical and easy-to-operate method. The genes encoding for β-amylase and α-transglucosidase were fused and co-displayed on the yeast cell surface of Yarrowia lipolytica which can convert liquefied starch to IMO in one step. The highest IMO purity of 75.3% was obtained using the displayed fusion-enzyme at 50 °C. This method showed potential application in IMO production.