Hollenbeck Emily C, Fong Jiunn C N, Lim Ji Youn, Yildiz Fitnat H, Fuller Gerald G, Cegelski Lynette
Department of Chemical Engineering, Stanford University, Stanford, California.
Department of Microbiology and Environmental Toxicology, UC Santa Cruz, Santa Cruz, California.
Biophys J. 2014 Nov 18;107(10):2245-52. doi: 10.1016/j.bpj.2014.10.015.
Biofilm formation increases both the survival and infectivity of Vibrio cholerae, the causative agent of cholera. V. cholerae is capable of forming biofilms on solid surfaces and at the air-liquid interface, termed pellicles. Known components of the extracellular matrix include the matrix proteins Bap1, RbmA, and RbmC, an exopolysaccharide termed Vibrio polysaccharide, and DNA. In this work, we examined a rugose strain of V. cholerae and its mutants unable to produce matrix proteins by interfacial rheology to compare the evolution of pellicle elasticity in real time to understand the molecular basis of matrix protein contributions to pellicle integrity and elasticity. Together with electron micrographs, visual inspection, and contact angle measurements of the pellicles, we defined distinct contributions of the matrix proteins to pellicle morphology, microscale architecture, and mechanical properties. Furthermore, we discovered that Bap1 is uniquely required for the maintenance of the mechanical strength of the pellicle over time and contributes to the hydrophobicity of the pellicle. Thus, Bap1 presents an important matrix component to target in the prevention and dispersal of V. cholerae biofilms.
生物膜的形成增加了霍乱弧菌（霍乱的病原体）的存活率和传染性。霍乱弧菌能够在固体表面和气液界面形成生物膜，即菌膜。细胞外基质的已知成分包括基质蛋白Bap1、RbmA和RbmC、一种称为霍乱弧菌多糖的胞外多糖以及DNA。在这项研究中，我们通过界面流变学研究了一株粗糙型霍乱弧菌及其无法产生基质蛋白的突变体，以实时比较菌膜弹性的演变，从而了解基质蛋白对菌膜完整性和弹性的贡献的分子基础。结合菌膜的电子显微照片、目视检查和接触角测量，我们确定了基质蛋白对菌膜形态、微观结构和机械性能的不同贡献。此外，我们发现Bap1是随着时间维持菌膜机械强度所独特需要的，并且有助于菌膜的疏水性。因此，Bap1是预防和分散霍乱弧菌生物膜时的一个重要靶向基质成分。
