Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
School of Food Science & Engineering, South China University of Technology, Guangzhou, China.
Int J Biol Macromol. 2018 Nov;119:312-319. doi: 10.1016/j.ijbiomac.2018.07.122. Epub 2018 Jul 20.
This study was to assess the protective effect of exopolysaccharide (EPS) produced by a medicinal fungus Cordyceps sinensis Cs-HK1 on Bifidobacteria against antibiotic inhibition. The high-molecular weight EPS fractions showed significant protective effect on all five bifidobacterial strains against four common antibiotics, leading to a dramatic increase in the minimal inhibitory and minimal bactericidal concentrations. The protective effect of EPS on the bacteria was probably attributed to the formation of a viscous layer around the bacterial cell resisting the access by the antibiotics. The EPS layer surrounding the bacteria cell also promoted the aggregation of bacteria and formation of biofilm as observed by microscopy. EPS also enhanced the bifidobacterial adhesion to Caco-2 cell monolayer. In general, the protective effect as well as biofilm formation due to EPS was significantly correlated with the molecular weight of EPS fractions.
本研究旨在评估药用真菌蛹虫草（Cordyceps sinensis Cs-HK1）产生的胞外多糖（EPS）对双歧杆菌对抗生素抑制的保护作用。高分子量 EPS 级分对所有五种双歧杆菌菌株均表现出显著的保护作用，能显著提高五种双歧杆菌对抗生素的最小抑菌浓度和最小杀菌浓度。EPS 对细菌的保护作用可能归因于在细菌细胞周围形成粘性层，阻止抗生素进入。通过显微镜观察，细菌细胞周围的 EPS 层也促进了细菌的聚集和生物膜的形成。EPS 还增强了双歧杆菌对 Caco-2 细胞单层的黏附。总的来说，由于 EPS 产生的保护作用和生物膜形成与 EPS 级分的分子量显著相关。
