Abstract Inulin has been widely used as a cheap bioresource for producing many valuable products by enzymatic hydrolysis or microbial fermentation, such as high-fructose syrup and fructooligosaccharides. In this work, a one-pot two-enzyme reaction system was developed to produce d -allulose from inulin using A. piperis exoinulinase and Dorea sp. d -Allulose 3-epimerase. The exoinulinase that was identified from Aspergillus piperis CBS 112811 was cloned and intracellularly expressed in Escherichia coli. The enzyme displayed the maximal activity as 3750 U mg−1 at pH 6.0 and 55 °C. For the effects of different cations, Mn2+ simulated the enzyme activity by 41 %. When 10 g L−1 inulin was hydrolyzed by A. piperis exoinulinase, the conversion rate reached 98 % within 6 h. Furthermore, the optimum pH, temperature and the ratio of the two enzymes loaded for one-pot reaction were measured to be pH 6.0, 60 °C and 15/15 U mL−1, respectively. The conversion rate of inulin to d -allulose reached 23.3 % after reaction for 4 h with 10 g L−1 inulin. When adding 100 g L−1 as a substrate, 21.4 g L−1 d -allulose was produced using the two-enzyme system.

中文翻译：

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通过来自胡椒曲霉和 Dorea sp. 的新型热稳定外切花粉酶从菊粉中一锅生产 d-阿洛酮糖。d-阿洛酮糖3-差向异构酶

摘要 菊粉作为一种廉价的生物资源被广泛用于通过酶水解或微生物发酵生产许多有价值的产品，如高果糖浆和低聚果糖。在这项工作中，开发了一种一锅式双酶反应系统，使用 A. piperis exoinulinase 和 Dorea sp. 从菊粉生产 d-阿洛酮糖。d-阿洛酮糖 3-差向异构酶。从胡椒曲霉 CBS 112811 中鉴定出的菊粉外切酶被克隆并在大肠杆菌中进行细胞内表达。该酶在 pH 6.0 和 55 °C 下显示出最大活性为 3750 U mg-1。对于不同阳离子的影响，Mn2+ 模拟了 41% 的酶活性。当 10 g L-1 菊粉被 A. piperis exoinulinase 水解时，转化率在 6 h 内达到 98%。此外，最佳pH值，测得的温度和一锅反应加载的两种酶的比例分别为 pH 6.0、60 °C 和 15/15 U mL-1。菊粉与 10 g L-1 菊粉反应 4 小时后，菊粉转化为 d-阿洛酮糖的转化率达到 23.3%。当添加 100 g L-1 作为底物时，使用双酶系统产生 21.4 g L-1 d-阿洛酮糖。