Development of a Bacterial Biosensor for Rapid Screening of Yeast p-Coumaric Acid Production

ACS Synth Biol. 2017 Oct 20;6(10):1860-1869. doi: 10.1021/acssynbio.7b00009. Epub 2017 Jun 21.

Abstract

Transcription factor-based biosensors are used to identify producer strains, a critical bottleneck in cell factory engineering. Here, we address two challenges with this methodology: transplantation of heterologous transcriptional regulators into new hosts to generate functional biosensors and biosensing of the extracellular product concentration that accurately reflects the effective cell factory production capacity. We describe the effects of different translation initiation rates on the dynamic range of a p-coumaric acid biosensor based on the Bacillus subtilis transcriptional repressor PadR by varying its ribosomal binding site. Furthermore, we demonstrate the functionality of this p-coumaric acid biosensor in Escherichia coli and Corynebacterium glutamicum. Finally, we encapsulate yeast p-coumaric acid-producing cells with E. coli-biosensing cells in picoliter droplets and, in a microfluidic device, rapidly sort droplets containing yeast cells producing high amounts of extracellular p-coumaric acid using the fluorescent E. coli biosensor signal. As additional biosensors become available, such approaches will find broad applications for screening of an extracellular product.

MeSH terms

  • Bacterial Proteins / metabolism
  • Biosensing Techniques / methods*
  • Corynebacterium glutamicum / metabolism
  • Coumaric Acids
  • Escherichia coli / metabolism
  • Propionates / metabolism*
  • Transcription Factors / metabolism

Substances

  • Bacterial Proteins
  • Coumaric Acids
  • Propionates
  • Transcription Factors
  • p-coumaric acid