Adaptive laboratory evolution of Escherichia coli under acid stress

Bin Du, Connor A. Olson, Anand V Sastry, Xin Fang, Patrick V. Phaneuf, Ke Chen, Muyao Wu, Richard Szubin, Sibei Xu, Ye Gao, Ying Hefner, Adam M Feist, Bernhard O Palsson*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The ability of Escherichia coli to tolerate acid stress is important for its survival and colonization in the human digestive tract. Here, we performed adaptive laboratory evolution of the laboratory strain E. coli K-12 MG1655 at pH 5.5 in glucose minimal medium. After 800 generations, six independent populations under evolution had reached 18.0 % higher growth rates than their starting strain at pH 5.5, while maintaining comparable growth rates to the starting strain at pH 7. We characterized the evolved strains and found that: (1) whole genome sequencing of isolated clones from each evolved population revealed mutations in rpoC appearing in five of six sequenced clones; and (2) gene expression profiles revealed different strategies to mitigate acid stress, which are related to amino acid metabolism and energy production and conversion. Thus, a combination of adaptive laboratory evolution, genome resequencing and expression profiling revealed, on a genome scale, the strategies that E. coli uses to mitigate acid stress.
Original languageEnglish
JournalMicrobiology
ISSN1350-0872
DOIs
Publication statusAccepted/In press - 2020

Keywords

  • Adaptive laboratory evolution
  • Acid stress
  • Escherichia coli
  • Whole genome resequencing
  • RNA sequencing

Cite this

Du, B., Olson, C. A., Sastry, A. V., Fang, X., Phaneuf, P. V., Chen, K., ... Palsson, B. O. (Accepted/In press). Adaptive laboratory evolution of Escherichia coli under acid stress. Microbiology. https://doi.org/10.1099/mic.0.000867