Biosensor-based high-throughput screening is efficient for improving industrial microorganisms. There is a severe shortage of human milk oligosaccharides (HMOs) biosensors. This study established a 3-fucosyllactose (3-FL, a kind of HMOs) whole-cell biosensor by coupling cell growth with production. To construct and optimize the biosensor, an 3-FL producer was engineered by deleting the , and genes, directing the mannose flux solely to 3-FL synthesis. Then, an α-L-fucosidase was introduced to hydrolyze 3-FL to fucose which was used as the only carbon source for cell growth. Using the biosensor, the 3-FL production of a screened mutant was improved by 25 % to 42.05 ± 1.28 g/L. The productivity reached 1.17 g/L/h, the highest level reported by now. The mutant obtained should be a new clue for the 3-FL overproduction mechanism. In summary, this study provided a novel approach to construct HMOs biosensors for strain improvement.

中文翻译：

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3-岩藻糖基乳糖全细胞生物传感器的构建及应用，用于高通量筛选过量生产者


基于生物传感器的高通量筛选可有效改善工业微生物。母乳低聚糖（HMO）生物传感器严重短缺。本研究通过耦合细胞生长与生产，建立了3-岩藻糖基乳糖（3-FL，一种HMO）全细胞生物传感器。为了构建和优化生物传感器，通过删除 、 和 基因来设计 3-FL 生产器，将甘露糖通量仅引导至 3-FL 合成。然后，引入α-L-岩藻糖苷酶将3-FL水解为岩藻糖，岩藻糖用作细胞生长的唯一碳源。使用生物传感器，筛选的突变体的 3-FL 产量提高了 25%，达到 42.05 ± 1.28 g/L。生产率达到 1.17 g/L/h，为目前报道的最高水平。获得的突变体应该是3-FL过量产生机制的新线索。总之，本研究提供了一种构建用于菌株改良的 HMO 生物传感器的新方法。