S100: Mapping the adaptive landscape using a combination of a novel adaptive evolution method and genomic tools

Robustness of biological systems is a complex phenotype and involves multiple genes and mechanisms.  The genetic determinants that are involved in enhanced tolerance to growth inhibitors in biological systems form the adaptive landscape for the phenotype; so in order to engineer more robust biocatalysts, a better understanding of the adaptive landscape is required.  Here, we used an adaptive laboratory evolution method called visualizing evolution in real time (VERT) to help map out part of the adaptive landscape of Escherichia coli tolerance to n-butanol.  Subsequent transcriptome and whole-genome resequencing analyses of the isolated adaptive mutants revealed different mechanisms of n-butanol resistance in different lineages.  Potentially new mechanism of n-butanol tolerance was elucidated from the data and will be discussed.