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Combining Inducible Lectin Expression and Magnetic Glyconanoparticles for the Selective Isolation of Bacteria from Mixed Populations

Petch, Joshua E.; Gurnani, Pratik; Yilmaz, Gokhan; Mastrotto, Francesca; Alexander, Cameron; Heeb, Stephan; C�mara, Miguel; Mantovani, Giuseppe

Combining Inducible Lectin Expression and Magnetic Glyconanoparticles for the Selective Isolation of Bacteria from Mixed Populations Thumbnail


Joshua E. Petch

Pratik Gurnani

Gokhan Yilmaz

Francesca Mastrotto

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Professor of Molecular Microbiology


The selective isolation of bacteria from mixed populations has been investigated in varied applications ranging from differential pathogen identification in medical diagnostics and food safety to the monitoring of microbial stress dynamics in industrial bioreactors. Selective isolation techniques are generally limited to the confinement of small populations in defined locations, may be unable to target specific bacteria, or rely on immunomagnetic separation, which is not universally applicable. In this proof-of-concept work, we describe a novel strategy combining inducible bacterial lectin expression with magnetic glyconanoparticles (MGNPs) as a platform technology to enable selective bacterial isolation from cocultures. An inducible mutant of the type 1 fimbriae, displaying the mannose-specific lectin FimH, was constructed in Escherichia coli allowing for "on-demand"glycan-binding protein presentation following external chemical stimulation. Binding to glycopolymers was only observed upon fimbrial induction and was specific for mannosylated materials. A library of MGNPs was produced via the grafting of well-defined catechol-terminal glycopolymers prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization to magnetic nanoparticles. Thermal analysis revealed high functionalization (?85% polymer by weight). Delivery of MGNPs to cocultures of fluorescently labeled bacteria followed by magnetic extraction resulted in efficient depletion of type 1 fimbriated target cells from wild-type or afimbriate E. coli. Extraction efficiency was found to be dependent on the molecular weight of the glycopolymers utilized to engineer the nanoparticles, with MGNPs decorated with shorter Dopa-(ManAA)50 mannosylated glycopolymers found to perform better than those assembled from a longer Dopa-(ManAA)200 analogue. The extraction efficiency of fimbriated E. coli was also improved when the counterpart strain did not harbor the genetic apparatus for the expression of the type 1 fimbriae. Overall, this work suggests that the modulation of the genetic apparatus encoding bacterial surface-associated lectins coupled with capture through MGNPs could be a versatile tool for the extraction of bacteria from mixed populations.

Journal Article Type Article
Acceptance Date Apr 2, 2021
Online Publication Date Apr 14, 2021
Publication Date Apr 28, 2021
Deposit Date Jun 21, 2021
Publicly Available Date Apr 15, 2022
Journal ACS Applied Materials and Interfaces
Print ISSN 1944-8244
Electronic ISSN 1944-8252
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 13
Issue 16
Pages 19230-19243
Public URL
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Additional Information This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces,copyright© American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see