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bioRxiv · 10.1101/229922

An orthogonal and pH-tunable sensor-selector for muconic acid biosynthesis in yeast

Snoek, T.·Romero-Suarez, D.·Zhang, J.·Skjoedt, M. L.·Sudarsan, S.·Jensen, M. K.·Keasling, J. D.
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Abstract

Microbes offer enormous potential for production of industrially relevant chemicals and therapeutics, yet the rapid identification of high-producing microbes from large genetic libraries is a major bottleneck in modern cell factory development. Here, we develop and apply a synthetic selection system in Saccharomyces cerevisiae that couples the concentration of muconic acid, a plastic precursor, to cell fitness by using the prokaryotic transcriptional regulator BenM driving an antibiotic resistance gene. We show the sensor-selector does not affect production, and find that tuning pH of the cultivation medium limits the rise of non-producing cheaters. We apply the sensor-selector to selectively enrich for best-producing variants out of a large library of muconic acid production strains, and identify an isolate that produced more than 2 g/L muconic acid in a bioreactor. We expect that this sensor-selector can aid the development of other synthetic selection systems based on allosteric transcription factors.

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Snoek, T., Romero-Suarez, D., Zhang, J., Skjoedt, M. L., Sudarsan, S., Jensen, M. K., Keasling, J. D.. 2017-12-06. An orthogonal and pH-tunable sensor-selector for muconic acid biosynthesis in yeast. https://doi.org/10.1101/229922

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