Inducible Bacterial Adhesion to Plastic Surfaces for Enhanced Biodegradation

Colonization of plastic surfaces by microbial biofilms offers a promising starting point for engineering efficient biodegradation systems. However, most studies to date focus on characterization or prevention of biofilms on plastics in diverse environments, and the potential biotechnological application for these systems has been underexplored. To address this, we report the efficient adhesion of Escherichia coli cells to a range of plastic surfaces through overexpression of two key determinants of bacterial biofilm formation: curli and antigen 43 (Ag43). A general trend of higher total biomass was observed from curli-mediated adhesion, but a more uniform adhesion was observed from Ag43 overexpression. We further demonstrate the application of this technology through the inducible adhesion of E. coli to polyethylene terephthalate (PET) surfaces and concurrent secretion of the PET depolymerase PHL7. Co-overexpression of curli fibers and secreted PHL7 resulted in a 5.6-fold increase in terephthalic acid release in comparison to the non-adherent control. These methods offer a general approach to inducible adhesion of genetically tractable cells to plastic surfaces and concurrent secretion of degradative enzymes and are anticipated to be broadly applicable across the field of plastic bioremediation technologies.