Adaptive laboratory evolution (ALE) is a powerful tool used to increase strain fitness in the presence of environmental stressors. If production and strain fitness can be coupled, ALE can be used to increase product formation. In earlier work, carotenoids hyperproducing mutants were obtained using an ALE strategy. Here, de novo mutations were identified in hyperproducers, and reconstructed mutants were explored to determine the exact impact of each mutation on production and tolerance. A single mutation in YMRCTy1-3 conferred increased carotenoid production, and when combined with other beneficial mutations led to further increased β-carotene production. Findings also suggest that the ALE strategy selected for mutations that confer increased carotenoid production as primary phenotype. Raman spectroscopy analysis and total lipid quantification revealed positive correlation between increased lipid content and increased β-carotene production. Finally, we demonstrated that the best combinations of mutations identified for β-carotene production were also beneficial for production of lycopene.

中文翻译：

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从实验室进化的酿酒酵母中鉴定出类胡萝卜素产生的有益突变。

自适应实验室进化（ALE）是一种强大的工具，可用于在存在环境压力源的情况下提高应变适应性。如果可以将生产和应变适应性结合起来，则可以使用ALE来增加产品的形成。在较早的工作中，使用ALE策略获得了类胡萝卜素高产突变体。在这里，在高产猪中鉴定了从头突变，并对重组突变体进行了研究，以确定每种突变对产量和耐受性的确切影响。YMRCTy1-3中的单个突变赋予增加的类胡萝卜素产量，当与其他有益突变结合使用时，可以进一步增加β-胡萝卜素的产生。研究结果还表明，ALE策略选择的突变可将类胡萝卜素的产生增加为主要表型。拉曼光谱分析和总脂质定量显示脂质含量增加与β-胡萝卜素产量增加之间呈正相关。最后，我们证明了针对β-胡萝卜素生产而确定的突变的最佳组合对于番茄红素的生产也是有益的。