Longitudinal single-cell chemical imaging of engineered strains reveals heterogeneity in fatty acid production
Longitudinal single-cell chemical imaging of engineered strains reveals heterogeneity in fatty acid production
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DOI：
10.1101/2021.07.26.453865
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
Nathan Tague;Haonan Lin;Jean-Baptiste Lugagne;Owen M. O’Connor;Deeya Burman;Wilson W. Wong;Ji‐Xin Cheng;M. Dunlop
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文献类型：
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作者：
Nathan Tague;Haonan Lin;Jean-Baptiste Lugagne;Owen M. O’Connor;Deeya Burman;Wilson W. Wong;Ji‐Xin Cheng;M. Dunlop
了解代谢异质性对于优化微生物生产有价值的化学物质至关重要，但需要能够随着时间的推移在单细胞水平上量化代谢物的工具。在这里，我们开发纵向高光谱受激拉曼散射（SRS）化学成像直接可视化游离脂肪酸在工程大肠杆菌在许多细胞周期。我们还开发了组成分析，以确定活细胞中脂肪酸的链长和不饱和度。我们的方法揭示了在许多代的过程中出现的殖民地之间和内部的脂肪酸生产的实质性异质性。有趣的是，菌株以酶依赖性方式显示不同类型的生产异质性。通过配对延时和SRS成像，我们在单细胞水平上研究了生长和生产之间的关系。单细胞定量未显示出在表现出高产量异质性的菌株中显著的生长-产量权衡。我们的研究结果表明，细胞间的生产异质性是普遍存在的，并提供了一种手段，连接单细胞和群体水平的生产。
Understanding metabolic heterogeneity is critical for optimizing microbial production of valuable chemicals, but requires tools that can quantify metabolites at the single-cell level over time. Here, we develop longitudinal hyperspectral stimulated Raman scattering (SRS) chemical imaging to directly visualize free fatty acids in engineered Escherichia coli over many cell cycles. We also develop compositional analysis to determine the chain length and unsaturation of the fatty acids in living cells. Our method reveals substantial heterogeneity in fatty acid production among and within colonies that emerges over the course of many generations. Interestingly, the strains display distinct types of production heterogeneity in an enzyme-dependent manner. By pairing time-lapse and SRS imaging, we examine the relationship between growth and production at the single-cell level. Single-cell quantification does not show a significant growth-production tradeoff in a strain that exhibits high production heterogeneity. Our results demonstrate that cell-to-cell production heterogeneity is pervasive and provide a means to link single-cell and population-level production.