Sarin Mineralization Using Engineered E. coli

Removing chemicals in contaminated environments or in stockpiles is sometimes difficult because of toxicity to humans. The Chemical Weapons Convention of 1993 called for the rapid depletion of sarin and soman stockpiles, both highly toxic nerve agents. We engineered E. coli to break down sarin and soman to benign inorganic phosphate, which is subsequently used for host growth. A key to this engineering effort was identifying a phosphodiesterase (PdeA) from Delftia acidovorans that demonstrated high efficiency and promiscuity in hydrolyzing diverse phosphonate esters. We improved the activity of PdeA for sarin and soman degrdation by directed enzyme evolution to levels that allowed sustained host growth in these agents as the sole phosphorus source.