Engineering Research Center of Health Food Design & Nutrition Regulation, Dongguan Key Laboratory of Typical Food Precision Design, China National Light Industry Key Laboratory of Healthy Food Development and Nutrition Regulation, School of Life and Health Technology, Dongguan University of Technology, Dongguan 523808, China; Research Institute for Future Food, Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Engineering Research Center of Health Food Design & Nutrition Regulation, Dongguan Key Laboratory of Typical Food Precision Design, China National Light Industry Key Laboratory of Healthy Food Development and Nutrition Regulation, School of Life and Health Technology, Dongguan University of Technology, Dongguan 523808, China.
Carbohydr Polym. 2024 Dec 1;345:122577. doi: 10.1016/j.carbpol.2024.122577. Epub 2024 Aug 3.
This study was to investigate the antibacterial effects and metabolites derived from bifidobacterial fermentation of an exopolysaccharide EPS-LM produced by a medicinal fungus Cordyceps sinensis, Cs-HK1. EPS-LM was a partially purified polysaccharide fraction which was mainly composed of Man, Glc and Gal at 7.31:12.95:1.00 mol ratio with a maximum molecular weight of 360 kDa. After fermentation of EPS-LM in two bifidobacterial cultures, B. breve and B. longum, the culture digesta showed significant antibacterial activities, inhibiting the proliferation and biofilm formation of Escherichia coli. Based on untargeted metabolomic profiling of the digesta, the levels of short chain fatty acids, carboxylic acids, benzenoids and their derivatives were all increased significantly (p < 0.01), which probably contributed to the enhanced antibacterial activity by EPS-LM. Since EPS-LM was only slightly consumed for the bifidobacterial growth, it mainly stimulated the biosynthesis of bioactive metabolites in the bifidobacterial cells. The results also suggested that EPS-LM polysaccharide may have a regulatory function on the bifidobacterial metabolism leading to production of antibacterial metabolites, which may be of significance for further exploration.
本研究旨在探讨虫草素发酵产生的一种真菌多糖 EPS-LM 的抗菌作用及其代谢产物。EPS-LM 是一种部分纯化的多糖，主要由 Man、Glc 和 Gal 组成，摩尔比为 7.31:12.95:1.00，分子量最大为 360 kDa。在两种双歧杆菌（B. breve 和 B. longum）发酵 EPS-LM 后，培养物消化液显示出显著的抗菌活性，抑制大肠杆菌的增殖和生物膜形成。基于消化液的非靶向代谢组学分析，短链脂肪酸、羧酸、苯类及其衍生物的水平均显著升高（p<0.01），这可能有助于增强 EPS-LM 的抗菌活性。由于 EPS-LM 仅被双歧杆菌轻微消耗，它主要刺激双歧杆菌细胞中生物活性代谢物的生物合成。研究结果还表明，EPS-LM 多糖可能对双歧杆菌代谢具有调节作用，从而产生抗菌代谢物，这对于进一步探索具有重要意义。
