Gluconobacter oxydans is important in the conversion of D-sorbitol into l-sorbose, which is an essential intermediate for industrial-scale production of vitamin C. In a previous study, the strain G. oxydans WSH-004 could directly produce 2-keto-l-gulonic acid (2-KLG). However, its D-sorbitol tolerance was poor compared with that of other common industrial G. oxydans strains, which grew well in the presence of more than 200 g/L of D-sorbitol. This study aimed to use the microbial microdroplet culture (MMC) system for the adaptive evolution of G. oxydans WSH-004 so as to improve its tolerance to high substrate concentration and high temperature. A series of adaptively evolved strains, G. oxydans MMC1-MMC10, were obtained within 90 days. The results showed that the best strain MMC10 grew in a 300 g/L of D-sorbitol medium at 40°C. The comparative genomic analysis revealed that genetic changes related to increased tolerance were mainly in protein translation genes. Compared with the traditional adaptive evolution method, the application of microdroplet-aided adaptive evolution could improve the efficiency in terms of reducing time and simplifying the procedure for strain evolution. This research indicated that the microdroplet-aided adaptive evolution was an effective tool for improving the phenotypes with undemonstrated genotypes in a short time.

中文翻译：

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通过微滴辅助自适应进化快速启用氧化葡糖杆菌对高 D-山梨糖醇浓度和高温的抵抗力。

Gluconobacter oxydans 在 D-山梨糖醇转化为 L-山梨糖方面很重要，L-山梨糖是工业规模生产维生素 C 的必要中间体。在之前的一项研究中，G. oxydans WSH-004 菌株可以直接生产 2-酮- l-古洛糖酸 (2-KLG)。然而，与其他常见的工业 G. oxydans 菌株相比，其 D-山梨糖醇耐受性较差，后者在超过 200 g/L 的 D-山梨糖醇存在下生长良好。本研究旨在利用微生物微滴培养（MMC）系统对 G. oxydans WSH-004 进行适应性进化，以提高其对高底物浓度和高温的耐受性。在 90 天内获得了一系列适应性进化的菌株 G. oxydans MMC1-MMC10。结果表明，最佳菌株 MMC10 在 300 g/L 的 D-山梨糖醇培养基中在 40°C 下生长。比较基因组分析表明，与耐受性增加相关的遗传变化主要发生在蛋白质翻译基因中。与传统的自适应进化方法相比，微滴辅助自适应进化的应用可以在减少时间和简化应变进化过程方面提高效率。该研究表明，微滴辅助的适应性进化是在短时间内改善未证实基因型的表型的有效工具。微滴辅助自适应进化的应用可以在减少时间和简化应变进化过程方面提高效率。该研究表明，微滴辅助的适应性进化是在短时间内改善未证实基因型的表型的有效工具。微滴辅助自适应进化的应用可以在减少时间和简化应变进化过程方面提高效率。该研究表明，微滴辅助的适应性进化是在短时间内改善未证实基因型的表型的有效工具。