Dolfi Stefania, Sveronis Aris, Silipo Alba, Rizzo Roberto, Cescutti Paola
Department of Life Sciences, Bldg C11, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy.
Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
Carbohydr Res. 2015 Jun 26;411:42-8. doi: 10.1016/j.carres.2015.04.012. Epub 2015 Apr 28.
Burkholderia multivorans C1576 is a Gram negative opportunistic pathogen causing serious lung infection in cystic fibrosis patients. Considering that bacteria naturally form biofilms, and exopolysaccharides are recognized as important factors for biofilm architecture set-up, B. multivorans was grown both in biofilm and in non-biofilm mode on two different media in order to compare the exopolysaccharides biosynthesized in these different experimental conditions. The exopolysaccharides produced were purified and their structure was determined resorting mainly to NMR spectroscopy, ESI mass spectrometry and gas chromatography coupled to mass spectrometry. The experimental data showed that both in biofilm and non-biofilm mode B. multivorans C1576 produced a novel exopolysaccharide having the following structure: [Formula: see text]. About 50% of the 2-linked rhamnose residues are substituted on C-3 with a methyl ether group. The high percentage of deoxysugar Rha units, coupled with OMe substitutions, suggest a possible role for polymer domains with marked hydrophobic characteristics able to create exopolysaccharide junction zones favouring the stability of the biofilm matrix.
多食伯克霍尔德菌C1576是一种革兰氏阴性机会致病菌，可在囊性纤维化患者中引起严重的肺部感染。考虑到细菌天然会形成生物膜，且胞外多糖被认为是生物膜结构形成的重要因素，为了比较在这些不同实验条件下生物合成的胞外多糖，将多食伯克霍尔德菌在两种不同培养基上分别以生物膜模式和非生物膜模式进行培养。对产生的胞外多糖进行纯化，并主要借助核磁共振光谱、电喷雾电离质谱以及气相色谱 - 质谱联用技术确定其结构。实验数据表明，无论是在生物膜模式还是非生物膜模式下，多食伯克霍尔德菌C1576均产生了一种具有以下结构的新型胞外多糖：[化学式：见原文]。约50%的2 - 连接鼠李糖残基在C - 3位被甲基醚基团取代。高比例的脱氧糖鼠李糖单元以及甲氧基取代表明，具有显著疏水特性的聚合物结构域可能发挥作用，能够形成有利于生物膜基质稳定性的胞外多糖连接区域。
