Importance of Pyruvate Sensing and Transport for the Resuscitation of Viable but Nonculturable Escherichia coli K-12

Abstract

Viable but nonculturable (VBNC) bacteria do not form colonies in standard medium but otherwise retain their metabolic activity and can express toxic proteins. Many bacterial genera, including Escherichia , Vibrio , and Listeria , have been shown to enter the VBNC state upon exposure to adverse conditions, such as low temperature, radiation, and starvation. Ultimately, these organisms pose a public health risk with potential implications for the pharmaceutical and food industries, as dormant organisms are especially difficult to selectively eliminate and VBNC bacteria can be resuscitated if placed in an environment with appropriate nutrition and temperature. Here we used a microfluidic system to monitor the resuscitation of single VBNC cells over time. We provide new molecular insights into the initiation of resuscitation by demonstrating that VBNC E. coli cells rapidly take up pyruvate with an inducible high-affinity transporter, whose expression is triggered by the BtsSR-YpdAB sensing network.