Department of Life Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy.
Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy.
Int J Biol Macromol. 2019 Sep 1;136:944-950. doi: 10.1016/j.ijbiomac.2019.06.140. Epub 2019 Jun 20.
Microorganisms often grow in communities called biofilms where cells are imbedded in a complex self-produced biopolymeric matrix composed mainly of polysaccharides, proteins, and DNA. This matrix, together with cell proximity, confers many advantages to these microbial communities, but also constitutes a serious concern when biofilms develop in human tissues or on implanted prostheses. Although polysaccharides are considered the main constituents of the matrices, their specific role needs to be clarified. We have investigated the chemical and morphological properties of the polysaccharide extracted from biofilms produced by the C1576 reference strain of the opportunistic pathogen Burkholderia multivorans, which causes lung infections in cystic fibrosis patients. The aim of the present study is the definition of possible interactions of the polysaccharide and the three-dimensional conformation of its chain within the biofilm matrix. Surface plasmon resonance experiments confirmed the ability of the polysaccharide to bind hydrophobic molecules, due to the presence of rhamnose dimers in its primary structure. In addition, atomic force microscopy studies evidenced an extremely compact three-dimensional structure of the polysaccharide which may form aggregates, suggesting a novel view of its structural role into the biofilm matrix.
微生物通常在称为生物膜的群落中生长，在那里细胞嵌入主要由多糖、蛋白质和 DNA 组成的复杂自身产生的生物聚合物基质中。该基质与细胞接近度一起为这些微生物群落赋予了许多优势，但当生物膜在人体组织或植入的假体上发育时，也构成了严重的问题。尽管多糖被认为是基质的主要成分，但它们的具体作用仍需要澄清。我们研究了从机会性病原体伯克霍尔德菌多形亚种 C1576 参考菌株产生的生物膜中提取的多糖的化学和形态特性，该菌会导致囊性纤维化患者的肺部感染。本研究的目的是定义多糖在生物膜基质中的可能相互作用及其链的三维构象。表面等离子体共振实验证实了多糖结合疏水分子的能力，这是由于其一级结构中存在鼠李糖二聚体。此外，原子力显微镜研究表明，多糖具有极其紧凑的三维结构，可能形成聚集体，这表明其在生物膜基质中的结构作用具有新的观点。
