Open AccessAdaptive laboratory evolution of Escherichia coli under acid stress
Author(s) -
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 Ø. Palsson
Publication year - 2020
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.352
H-Index - 35
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.000867
Subject(s) - escherichia coli , biology , genome , strain (injury) , population , gene , bacteria , genetics , whole genome sequencing , adaptive evolution , phenotype , microbiology and biotechnology , demography , sociology , anatomy
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.