The selective sequestration of bacterial populations using polymeric glycomaterials

Abstract

The ability to selectively sequester bacteria from a mixed population is a desirable aim across a range of fields. Already some technologies exist to attempt to meet these aims spanning microfluidics and automated flow cytometry to antibody conjugated magnetic nanoparticle precipitation. However, these technologies are generally limited to the confinement of small populations in defined locations. Furthermore they may not be able to differentiate morphologically similar but phenotypically divergent cells. We aim to produce a novel technology to isolate bacteria from mixed populations by utilising polymeric carbohydrate ligands which bind to inducible bacterial adhesion proteins. To achieve this aim an inducible mutant of the fim operon in Escherichia coli has be constructed, thus allowing for switchable production of the mannose binding organelle, Type 1 fimbriae. Furthermore, we have previously observed that mannosylated polymers selectively bind to Type 1 fimbriated E. coli and to our induced mutant. Novel mannose functionalised polymers are being synthesised via a reversible addition-fragmentation chain transfer (RAFT) scheme. These polymers contain a catechol terminus which may be conjugated to magnetic Fe3O4 nanoparticles thus facilitating selective bacterial sequestration by magnetic separation. The successful development of this polymer-based bacterial sequestration platform could potentially enable the equivalent of immunoprecipitation in large-scale fermentation processes or the precise manipulation of living cells in laboratory scale procedures.