School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Biorefinery Research Institution, Nanjing University of Science and Technology, Nanjing 210094, China.
Sci Adv. 2023 Feb 3;9(5):eadd8835. doi: 10.1126/sciadv.add8835. Epub 2023 Feb 1.
The isomerization of xylose to xylulose is considered the most promising approach to initiate xylose bioconversion. Here, phylogeny-guided big data mining, rational modification, and ancestral sequence reconstruction strategies were implemented to explore new active xylose isomerases (XIs) for . Significantly, 13 new active XIs for were mined or artificially created. Moreover, the importance of the amino-terminal fragment for maintaining basic XI activity was demonstrated. With the mined XIs, four efficient xylose-utilizing were constructed and evolved, among which the strain CRD5HS contributed to ethanol titers as high as 85.95 and 94.76 g/liter from pretreated corn stover and corn cob, respectively, without detoxifying or washing pretreated biomass. Potential genetic targets obtained from adaptive laboratory evolution were further analyzed by sequencing the high-performance strains. The combined XI mining methods described here provide practical references for mining other scarce and valuable enzymes.
木糖异构化为木酮糖被认为是启动木糖生物转化最有前途的方法。在这里，我们实施了基于系统发育的大数据挖掘、合理修饰和祖先序列重建策略，以探索用于 的新型活性木糖异构酶（XIs）。值得注意的是，我们从 中挖掘或人工创建了 13 种新型活性 XIs。此外，还证明了氨基末端片段对于维持基本 XI 活性的重要性。利用挖掘到的 XIs，构建并进化了四种高效利用木糖的 ，其中菌株 CRD5HS 分别从预处理的玉米秸秆和玉米芯中贡献了高达 85.95 和 94.76 g/L 的乙醇产量，而无需对预处理的生物质进行解毒或清洗。通过对高性能菌株进行测序，进一步分析了适应性实验室进化获得的潜在遗传靶标。这里描述的综合 XI 挖掘方法为挖掘其他稀缺和有价值的酶提供了实用参考。
