Multilayered genetic safeguards limit growth of microorganisms to synthetic environments - Escape Mutant Sequencing. Escherichia coli str. K-12 substr. MG1655

We have constructed strains of Escherichia coli, whose viability is restricted to defined synthetic environments. This biocontainment strategy seeks to address issues of biosafety, particularly in the use of genetically modified organisms in open clinical or environmental settings. Our strains require exogenously supplied small molecules for viability, and therefore are unable to proliferate in natural environments. Some of these strains, at very low frequency, can find mechanisms to escape containment, allowing then to regain the ability to survive in natural environments. Whole Genome Sequencing of these escape mutants was conducted to help elucidate the genetic mechanisms of escape.