Cellodextrins are linear β-1,4-gluco-oligosaccharides that are soluble in water up to a degree of polymerization (DP) of ≈6. Soluble cellodextrins have promising applications as nutritional ingredients. A DP-controlled, bottom-up synthesis from expedient substrates is desired for their bulk production. Here, a three-enzyme glycoside phosphorylase cascade is developed for the conversion of sucrose and glucose into short-chain (soluble) cellodextrins (DP range 3-6). The cascade reaction involves iterative β-1,4-glucosylation of glucose from α-glucose 1-phosphate (αGlc1-P) donor that is formed in situ from sucrose and phosphate. With final concentration and yield of the soluble cellodextrins set as targets for biocatalytic synthesis, three major factors of reaction efficiency are identified and partly optimized: the ratio of enzyme activity, the ratio of sucrose and glucose, and the phosphate concentration used. The efficient use of the phosphate/αGlc1-P shuttle for cellodextrin production is demonstrated and the soluble product at 40 g L-1 is obtained under near-complete utilization of the donor substrate offered (88 mol% from 200 mm sucrose). The productivity is 16 g (L h)-1 . Through a simple two-step route, the soluble cellodextrins are recovered from the reaction mixture in ≥95% purity and ≈92% yield. Overall, this study provides the basis for their integrated production.

中文翻译：

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三酶磷酸化酶级联，用于短链纤维糊精的综合生产。

纤维糊精是线性的β-1,4-葡萄糖寡糖，可溶于水，聚合度（DP）约为≈6。可溶性纤维糊精作为营养成分具有广阔的应用前景。从适宜的底物进行DP控制的自下而上的合成对于它们的批量生产是期望的。在这里，开发了一种三酶糖苷磷酸化酶级联反应，用于将蔗糖和葡萄糖转化为短链（可溶性）纤维糊精（DP范围3-6）。级联反应涉及来自蔗糖和磷酸盐原位形成的α-葡萄糖1-磷酸（αGlc1-P）供体的葡萄糖的迭代β-1,4-葡萄糖基化。将可溶性纤维糊精的最终浓度和收率设定为生物催化合成的目标，确定并部分优化了反应效率的三个主要因素：酶活性比，蔗糖和葡萄糖的比例以及所用的磷酸盐浓度。证明了磷酸盐/αGlc1-P穿梭的有效利用来生产纤维糊精，并且在几乎完全利用所提供的供体底物（200 mol蔗糖中88 mol％）的情况下获得了40 g L-1的可溶性产物。生产率为16 g（L h）-1。通过简单的两步法，可从反应混合物中回收可溶性纤维糊精，纯度≥95％，产率约92％。总的来说，这项研究为他们的综合生产提供了基础。生产率为16 g（L h）-1。通过简单的两步法，可从反应混合物中回收可溶性纤维糊精，纯度≥95％，产率约92％。总的来说，这项研究为他们的综合生产提供了基础。生产率为16 g（L h）-1。通过简单的两步法，可从反应混合物中回收可溶性纤维糊精，纯度≥95％，产率约92％。总的来说，这项研究为他们的综合生产提供了基础。