Maltoheptaose as malto-oligosaccharides with specific degree of polymerization, has wide applications in food, medicine and cosmetics industries. Currently, cyclodextrinase have been applied as prepared enzyme to prepare maltoheptaose. However, the yield and proportion of maltoheptaose was lower, which is due to limited substrate and product specificity of cyclodextrinase (CDase). To achieve higher maltoheptaose yield, cyclodextrinase with high substrate and product specificity should be obtained. In this study, cyclodextrinase derived from Thermococcus sp B1001 (TsCDase) was successfully expressed and characterized in Bacillus subtilis for the first time. The specific activity of TsCDase was 637.95 U/mg under optimal conditions of 90 °C and pH 5.5, which exhibited high substrate specificity for cyclodextrins (CDs). When the concentration of β-CD was 8%, the yield of maltoheptaose achieved by TsCDase was 82.33% across all reaction products, which exceeded the yields of maltoheptaose in other recent reports. Among malto-oligosaccharides generated as reaction products, maltoheptaose was present in the highest proportion, about 94.55%. This study provides high substrate and product specificity of TsCDase. TsCDase is able to prepare higher yield of maltoheptaose through conversion of β-CD in the food industry.

中文翻译：

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嗜热球菌sp的环糊精酶在枯草芽孢杆菌中表达及其在麦芽七糖制备中的应用。

麦芽七糖作为具有特定聚合度的麦芽寡糖，在食品，医药和化妆品行业具有广泛的应用。目前，环糊精酶已被用作制备麦芽七糖的制备酶。然而，麦芽七糖的产率和比例较低，这是由于环糊精酶（CDase）的底物和产物特异性有限。为了获得更高的麦芽庚糖产量，应获得具有高底物和产物特异性的环糊精酶。在这项研究中，首次在枯草芽孢杆菌中成功表达并鉴定了源自嗜热球菌B1001的环糊精酶（TsCDase）。在90°C和pH 5.5的最佳条件下，TsCDase的比活性为637.95 U / mg，对环糊精（CDs）表现出高底物特异性。当β-CD的浓度为8％时，所有反应产物中TsCDase产生的麦芽七糖的产率为82.33％，超过了其他最近报道的麦芽七糖的产率。在作为反应产物生成的麦芽低聚糖中，麦芽七糖的含量最高，约为94.55％。该研究提供了TsCDase的高底物和产物特异性。TsCDase能够通过在食品工业中转化β-CD来制备更高产量的麦芽七糖。该研究提供了TsCDase的高底物和产物特异性。TsCDase能够通过在食品工业中转化β-CD来制备更高产量的麦芽七糖。该研究提供了TsCDase的高底物和产物特异性。TsCDase能够通过在食品工业中转化β-CD来制备更高产量的麦芽七糖。