P162: Visualizing evolution in real-type (VERT) as a tool for the engineering of microbial systems

Most of the industrially relevant uses of biological systems can be described for complex phenotypes, involving multiple genes and mechanisms.  Complex phenotypes are usually poorly understood, making the rational engineering of strains challenging.  Industrially relevant phenotypes described for complex phenotypes include product inhibition or inhibition due to adverse operational conditions.  If the desired trait can be coupled with growth, laboratory adaptive evolution can be used to improve the desired phenotype.  Characterization of the adaptive landscape will significantly enhance our knowledge on the important parameters underlying complex phenotypes needed for the rational engineering of strains.  Detailed molecular characterization of adaptive mutants isolated from laboratory evolution experiments provides insights into the adaptive landscape for the phenotype of interest.  However, traditional laboratory evolution methods have several limitations, such as the lack of rational schemes for the isolation of adaptive mutants and the ramp-up in selective pressure.  We demonstrate the utilization of a novel methodology called Visualizing Evolution in Real-Time (VERT), to help track the rise and expansion of adaptive mutants along the evolutionary experiment and to facilitate the isolation of adaptive mutants for further analysis and characterization.  This method was applied to both E. coli and yeast for enhancing biofuels tolerance.