title: Impacts of pH-mediated EPS structure on probiotic bacterial pili-whey proteins interactions.
abstract: Probiotic bacteria are routinely incorporated into dairy foods because of the health benefits they can provide when consumed. In this work, the marked pH-dependence of the pili/EPS organization at the outer surface of Lactobacillus rhamnosus GG is characterized in detail by Single Cell Force Microscopy and cell electrophoretic mobility measurements analyzed according to formalisms for nanomechanical contact and soft particle electrokinetics, respectively. At pH 6.8, LGG pili are easily accessible by AFM tips functionalized with whey proteins for specific binding, while at pH 4.8 the collapsed EPS surface layer significantly immobilized the LGG pili. This resulted in their reduced accessibility to the specific whey-coated AFM tip, and to stronger whey protein-pili rupture forces. Thus, pili interactions with whey proteins are screened to an extent that depends on the pH-mediated embedment of the pili within the EPS layer.
authors.affiliation: Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, TSA 40602, F-54518 Vandoeuvre lès Nancy, France.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Burgain
authors.affiliation: Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, TSA 40602, F-54518 Vandoeuvre lès Nancy, France.
authors.forename: Joel
authors.initials: J
authors.lastname: Scher
authors.affiliation: KU Leuven, Center of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium; University of Antwerp, Department of Bioscience Engineering, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lebeer
authors.affiliation: KU Leuven, Center of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium.
authors.forename: Jos
authors.initials: J
authors.lastname: Vanderleyden
authors.affiliation: Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, TSA 40602, F-54518 Vandoeuvre lès Nancy, France.
authors.forename: Magda
authors.initials: M
authors.lastname: Corgneau
authors.affiliation: Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, TSA 40602, F-54518 Vandoeuvre lès Nancy, France.
authors.forename: Justine
authors.initials: J
authors.lastname: Guerin
authors.affiliation: Université de Lorraine, LIEC, Laboratoire Interdisciplinaire des Environnements Continentaux, UMR 7360, Vandoeuvre-lès-Nancy F-54501, France; CNRS, LIEC, UMR 7360, Vandoeuvre-lès-Nancy, F-54501, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Caillet
authors.affiliation: Université de Lorraine, LIEC, Laboratoire Interdisciplinaire des Environnements Continentaux, UMR 7360, Vandoeuvre-lès-Nancy F-54501, France; CNRS, LIEC, UMR 7360, Vandoeuvre-lès-Nancy, F-54501, France.
authors.forename: Jérôme F L
authors.initials: JF
authors.lastname: Duval
authors.affiliation: Université de Lorraine, LCPME, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, UMR 7564, 54600 Villers-lès-Nancy, France.
authors.forename: Gregory
authors.initials: G
authors.lastname: Francius
authors.affiliation: Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, TSA 40602, F-54518 Vandoeuvre lès Nancy, France. Electronic address: claire.gaiani@univ-lorraine.fr.
authors.forename: Claire
authors.initials: C
authors.lastname: Gaiani
mesh_terms: D024202:Electrophoretic Mobility Shift Assay; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D052201:Lacticaseibacillus rhamnosus; D018625:Microscopy, Atomic Force; D019936:Probiotics; D000067816:Whey Proteins / Q000378:metabolism*
chemical_list: D000067816:Whey Proteins
keywords: Adhesion; Atomic force microscopy; Electrophoretic mobility; Milk proteins; Probiotic