Deciphering the aggregation mechanism of bacteria (Shewanella oneidensis MR1) in the presence of polyethyleneimine: Effects of the exopolymeric superstructure and polymer molecular weight - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Colloids and Surfaces B: Biointerfaces Année : 2016

Deciphering the aggregation mechanism of bacteria (Shewanella oneidensis MR1) in the presence of polyethyleneimine: Effects of the exopolymeric superstructure and polymer molecular weight

Résumé

Aggregation tests between bacteria and Polyethyleneimine (PEI) of low (600 g/mol) and high (750,000 g/mol) molecular weight were performed in order to address the physico-chemical mechanisms underlying the interactions between cationic polymer and bacterial membranes. The selected strain, Schewanella oneidensis MR-1, produces a lipopolysaccharide (LPS) of various lengths depending on the growth conditions. Optical density, bioaggregate size, electrophoretic mobility measurements, TEM and AFM observations, and cell lysis tests (crystal violet release), were collected to describe the PEI-mediated aggregation of LPS-O-antigen-free and LPS-O-antigen-decorated bacteria. The results show that PEI of low molecular weight (600 g/mol) fails to aggregate bacteria, whereas PEIs of higher molecular weight (60,000 and 750,000 g/mol) lead to flocculation at low polymer concentrations. In addition, the LPS-O antigen bacterial superstructure is shown to act as a protective barrier, thus delaying the harmful effects of the cationic polymer. Despite this protection, the interaction of bacterial membranes with increasing concentrations of PEI leads to a series of deleterious processes including biosurface modification (peeling, membrane permeabilization and/or lysis), aggregation of bacterial cells, and complexation of PEI with both released biosurface fragments and cytoplasmic residues issued from lysis.
Fichier principal
Vignette du fichier
Text Krapf et al.pdf (229.25 Ko) Télécharger le fichier
Figures Krapf et al.pdf (1.48 Mo) Télécharger le fichier
Graphical Abstract Krapf et al.pdf (492.65 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-02145608 , version 1 (03-06-2019)

Identifiants

Citer

Marie-Eve Krapf, Bruno Lartiges, Christophe Merlin, Gregory Francius, Jaafar Ghanbaja, et al.. Deciphering the aggregation mechanism of bacteria (Shewanella oneidensis MR1) in the presence of polyethyleneimine: Effects of the exopolymeric superstructure and polymer molecular weight. Colloids and Surfaces B: Biointerfaces, 2016, 139, pp.285-293. ⟨10.1016/j.colsurfb.2015.12.015⟩. ⟨hal-02145608⟩
250 Consultations
254 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More