Université de Lorraine, LIBio, Laboratoire d'Ingénierie des Biomolécules, 2 av de la Forêt de Haye, BP 172, 54505 Vandoeuvre-lès-Nancy, France.
Colloids Surf B Biointerfaces. 2013 Apr 1;104:153-62. doi: 10.1016/j.colsurfb.2012.11.032. Epub 2012 Dec 7.
Interactions between microbial cells and milk proteins are important for cell location into dairy matrices. In this study, interactions between two probiotic strains, Lactobacillus rhamnosus GG and Lactobacillus rhamnosus GR-1, and milk proteins (micellar casein, native and denatured whey proteins) were studied. The bacterial surface characterization was realized with X-ray photoelectron spectroscopy (XPS) to evaluate surface composition (in terms of proteins, polysaccharides and lipid-like compounds) and electrophoretic mobility that provide information on surface charge of both bacteria and proteins along the 3-7 pH range. In addition, atomic force microscopy (AFM) enabled the identification of specific interactions between bacteria and whey proteins, in contrast to the observed nonspecific interactions with micellar casein. These specific events appeared to be more important for the GG strain than for the GR-1 strain, showing that matrix interaction is strain-specific. Furthermore, our study highlighted that in addition to the nature of the strains, many other factors influence the bacterial interaction with dairy matrix including the nature of the proteins and the pH of the media.
微生物细胞与乳蛋白之间的相互作用对于细胞在乳制品基质中的定位非常重要。在这项研究中，研究了两种益生菌菌株乳杆菌 GG 和乳杆菌 GR-1 与乳蛋白（胶束酪蛋白、天然和变性乳清蛋白）之间的相互作用。利用 X 射线光电子能谱（XPS）对细菌表面特性进行了表征，以评估表面组成（蛋白质、多糖和类脂化合物）和电泳迁移率，电泳迁移率提供了关于两种细菌和蛋白质在 3-7 pH 范围内表面电荷的信息。此外，原子力显微镜（AFM）能够识别细菌与乳清蛋白之间的特异性相互作用，而与胶束酪蛋白观察到的非特异性相互作用相反。与 GR-1 菌株相比，这些特异性事件对 GG 菌株似乎更为重要，表明基质相互作用是菌株特异性的。此外，我们的研究强调，除了菌株的性质外，许多其他因素也会影响细菌与乳制品基质的相互作用，包括蛋白质的性质和介质的 pH 值。
