Millet Larry J, Vélez Jessica M, Michener Joshua K
Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37830 , United States.
The Joint Research Activity Unit of The Bredesen Center for Interdisciplinary Research and Graduate Education , University of Tennessee , Knoxville , Tennessee 37996 , United States.
ACS Synth Biol. 2019 Aug 16;8(8):1737-1743. doi: 10.1021/acssynbio.9b00226. Epub 2019 Aug 5.
Biosensors can be used to screen or select for small molecule production in engineered microbes. However, mutations to the biosensor that interfere with accurate signal transduction are common, producing an excess of false positives. Strategies have been developed to avoid this limitation by physically separating the production pathway and biosensor, but these approaches have only been applied to screens, not selections. We have developed a novel biosensor-mediated selection strategy using competition between cocultured bacteria. When applied to the biosynthesis of ,-muconate, we show that this strategy yields a selective advantage to producer strains that outweighs the costs of production. By encapsulating the competitive cocultures into microfluidic droplets, we successfully enriched the muconate-producing strains from a large population of control nonproducers. Facile selections for small molecule production will increase testing throughput for engineered microbes and allow for the rapid optimization of novel metabolic pathways.
生物传感器可用于筛选或选择工程微生物中的小分子生产。然而，干扰精确信号转导的生物传感器突变很常见，会产生过多的假阳性。已经开发出策略通过物理分离生产途径和生物传感器来避免这一限制，但这些方法仅应用于筛选，而非选择。我们开发了一种利用共培养细菌之间的竞争的新型生物传感器介导的选择策略。当应用于衣康酸的生物合成时，我们表明该策略为生产菌株带来的选择优势超过了生产成本。通过将竞争性共培养物封装到微流控液滴中，我们成功地从大量对照非生产菌株中富集了产衣康酸的菌株。小分子生产的便捷选择将提高工程微生物的测试通量，并允许快速优化新型代谢途径。
