CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Braz J Microbiol. 2023 Mar;54(1):199-211. doi: 10.1007/s42770-022-00842-x. Epub 2022 Nov 12.
The exploration of polysaccharides from microorganisms is of great importance. In this study, a new type of exopolysaccharide excreted by Fusarium merismoides A6 (FM-EPS) was isolated, and the extraction conditions were optimized using a response surface methodology (RSM). The extraction temperature at 0 °C, a precipitation time of 7.83 h, and an ethanol precipitation concentration of 77.64% were predicted and proved to be the best extraction conditions with the maximum extraction yield of 0.74 g/mL. Then, two fractions of F. merismoides A6 exopolysaccharides (FM-EPS1 and FM-EPS2) were obtained through DEAE Sepharose fast flow column chromatography. As indicated by monosaccharide composition analysis, both fractions mainly consisted of mannose, glucose, galactose, and ribose, with an average molecular weight of 5.14 × 10 and 6.50 × 10 g/mol, respectively. FT-IR and NMR spectroscopy indicated the FM-EPSs had both α- and β-glycosidic bonds. Moreover, the determination of antioxidant and antiproliferative activities in vitro proved that FM-EPSs had good antioxidant activities and antiproliferation activities. FM-EPS1 showed stronger antioxidant activities than FM-EPS2. FM-EPS2 showed antiproliferation activities on HeLa and HepG2 cells, while FM-EPS1 had no obvious antiproliferative activity. Therefore, FM-EPSs could be explored as potential antioxidant and anticancer agent applied in food, feed, nutraceutical, pharmaceutical, cosmetics, and chemical industries.
微生物多糖的研究具有重要意义。本研究从粉红镰刀菌 A6（FM-EPS）中分离得到一种新型胞外多糖，采用响应面法优化其提取条件。预测并验证最佳提取条件为提取温度 0℃、沉淀时间 7.83 h、乙醇沉淀浓度 77.64%，最大提取率为 0.74 g/mL。然后，通过 DEAE Sepharose fast flow 柱层析得到两种粉红镰刀菌 A6 胞外多糖（FM-EPS1 和 FM-EPS2）。单糖组成分析表明，两种多糖均由甘露糖、葡萄糖、半乳糖和核糖组成，平均分子量分别为 5.14×10 和 6.50×10 g/mol。FT-IR 和 NMR 光谱表明 FM-EPS 具有α-和β-糖苷键。此外，体外抗氧化和增殖活性测定表明，FM-EPS 具有良好的抗氧化和增殖抑制活性。FM-EPS1 表现出比 FM-EPS2 更强的抗氧化活性。FM-EPS2 对 HeLa 和 HepG2 细胞具有增殖抑制活性，而 FM-EPS1 无明显的增殖抑制活性。因此，FM-EPS 可作为潜在的抗氧化和抗癌药物应用于食品、饲料、营养保健品、制药、化妆品和化工行业。
