Novel hybrid biofilm system using synthetically engineered curli fibres

Abstract

Hydraulic fracturing, a popular mining technique, generates heavy metal contamination in nearby freshwater aquifers. This poses a threat to both the surrounding ecosystems an human health if exposed. Existing methods of heavy metal removal can produce additional hazardous byproducts. This proposal presents the use of a hybrid biofilm filter containing graphene and curli fibres with metal binding sites. Curli fibres are amyloid fibrils found on the extracellular biofilm of Escherichia coli (E coli.). Through the use of plasmid vectors, E. coliwill be engineered to produce secreted curli fibres with metal-binding residues. The stability and cohesive properties of the curli fibres augments the adherence to the graphene scaffolding, thus allowing for generation of a hybrid biofilm. With the filtration design and various experimental controls proposed, this model is ready for empirical proof of concept and subsequent quantitative optimization.