Rapid Acquisition of Gigapascal-High-Pressure Resistance by <named-content content-type="genus-species">Escherichia coli</named-content>

Abstract

ABSTRACT Pressure and temperature are important environmental variables that influence living systems. However, while they vary over a considerable range on Earth and other planets, it has hardly been addressed how straightforwardly and to what extent cellular life can acquire resistance to extremes of these parameters within a defined genomic context and a limited number of generations. Nevertheless, this is a very pertinent question with respect to the penetration of life in allegedly inhospitable environments. In this study, directed evolution was used to reveal the potential of the nonsporulating and mesophilic model bacterium Escherichia coli to develop the ability to survive exposure to high temperature or pressure. While heat resistance could only marginally be increased, our data show that piezoresistance could readily and reproducibly be extended into the GPa range, thereby greatly exceeding the currently recognized maximum for growth or survival. IMPORTANCE While extremophilic microorganisms generally serve as the reference for microbial survival capacities in inhospitable environments, we set out to examine how readily a mesophilic model bacterium such as Escherichia coli could build up resistance to extremes of temperature or pressure within a very short evolutionary time scale. Both heat and high pressure constitute ecologically important physical stresses that are able to irrevocably penetrate the entire cell. Our results for the first time establish that cellular life can acquire resistance to pressures extending into the GPa range.