[ACS Synthetic Biology] Development of a bacterial biosensor for rapid screening of yeast p-coumaric
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.
Solvej Siedler, Narendar K. Khatri, Andrea Zsohár, Inge Kjærbølling, Michael Vogt, Petter Hammar, Christian Førgaard Nielsen, Jan Marienhagen, Morten Otto Alexander O. A. Sommer, and Haakan N. Joensson ACS Synth. Biol., Just Accepted Manuscript DOI: 10.1021/acssynbio.7b00009 Publication Date (Web): May 23, 2017 Copyright © 2017 American Chemical Society