Abstract

With growing environmental concerns, industries are increasingly relying on the use of biofuels. Biodiesel storage tanks are susceptible to water infiltration that often results in the formation of biofilms containing bacteria and fungi. Biofilms may clog pipes, degrade fuel, or corrode storage tanks. We set out to engineer a “seek, aim, and destroy” system for the remediation of microbial biofilm. Pseudomonas aeruginosa, commonly found in fuel biofilms, releases the quorum sensing molecule C4-HSL. Our engineered E. coli cells express CheZ protein in response to a concentration gradient of C4-HSL to activate the flagella motors and propel the cells towards the biofilm. In addition, the engineered E. coli expresses chitinase on its surface and secretes cinnamaldehyde. Chitinase breaks down chitin in the fungal cell walls, increasing the ability of cinnamaldehyde to destroy the fungi. Cinnamaldehyde also eliminates bacteria, thus remediating the biofilm.