Adaptations Accumulated under Prolonged Resource Exhaustion Are Highly Transient

Many bacterial species, including the model bacterium Escherichiacoli, can survive for decades under starvation, following theexhaustion of external growth resources. We have previously shown thatE. coli genetically adapts under these conditions in a manner thatreduces its ability to grow once resources again become available.Here we study how E.coli populations that have been subject to veryprolonged resource exhaustion recover from costs associated with theiradaptation. We demonstrate that rapid adaptations acquired underprolonged starvation tend to be highly transient, rapidly reducing infrequency once bacteria are no longer starved. Our results shed lighton the longer-term consequences of bacterial survival under prolongedstarvation. More generally, these results may also be applicable tounderstanding longer-term consequences of rapid adaptation toadditional conditions as well.