本研究以羊栖菜为原料，分析了热水提取、超声辅助水提法、脉冲电场辅助水提法和纤维素酶辅助水提法4种提取方法所得多糖的理化性质和益生活性。首先对4个多糖的得率、分子量、单糖组成和流变特性进行了测定，然后将4个多糖分别添加到乳杆菌发酵培养基中替代葡萄糖作为碳源进行体外发酵，以评价其促进乳杆菌增殖活性的能力。结果表明，纤维素酶辅助水提取（E-SFP）所得多糖的得率最高，为14.02%，其次分别为超声辅助水提取U-SFP（12.57%）、脉冲辅助水提取P-SFP（10.38%）、热水提取H-SFP（7.07%）；4个多糖的平均分子量在200~245 ku之间，主要由岩藻糖、葡萄糖、半乳糖、甘露糖和木糖组成，岩藻糖和半乳糖是主要成分，其中E-SFP的单糖组成中葡萄糖的含量较其它3个多糖的高，达到了19.57%；4个多糖为典型的非牛顿流体，且表观粘度与分子量呈正相关；与空白组比较，4个多糖都能一定程度促进乳杆菌的增殖，其中E-SFP的促增殖作用显著高于其它3个多糖（p<0.05）（发酵48 h，OD600值达到0.50）。综合比较发现，采用纤维素酶辅助水提取所得羊栖菜多糖的得率最高，对乳杆菌的增殖活性最佳，本研究结果可为羊栖菜多糖的制备及其益生活性研究提供参考依据。

In the present study, Sargassum fusiforme was used as the raw materials, and the physicochemical properties and probiotic activity of its polysaccharides extracted by hot water extraction, ultrasonic-assisted water extraction, pulsed electric field-assisted water extraction and cellulase-assisted water extraction were examined. Firstly, the yield, molecular weight, monosaccharide composition and rheological properties of the four polysaccharides were determined. Then, the four polysaccharides were added to the fermentation medium of Lactobacillus to replace glucose as the carbon source for in vitro fermentation to evaluate its ability to promote the proliferation activity of Lactobacillus. The results showed that the yield of the polysaccharide obtained by the cellulase-assisted water extraction (E-SFP) was the highest (14.02%), followed by ultrasonic-assisted water extraction (U-SFP; 12.57%), pulse-assisted water extraction (P-SFP; 10.38%) and hot-water extraction (SFP; 7.07%). The four polysaccharides had an average molecular weight ranging from 200 to 245 ku, and consisted mainly of fucose, glucose, galactose, mannose and xylose, with the content of glucose in E-SFP (19.57%) higher than those of the other three polysaccharides. The solutions of the four polysaccharides were typical non-Newtonian fluids, and their apparent viscosities were positively correlated with their molecular weights. Compared with the blank group, four polysaccharides were found to promote the proliferation of Lactobacillus, among which E-SFP had a significantly greater proliferation-promoting effect than the other three polysaccharides (p<0.05) (fermentation for 48 h, OD600 value up to 0.50). Comprehensive comparisons revealed that the polysaccharides obtained by the cellulase-assisted water extraction method had the highest yield and strongest proliferation activity on Lactobacillus. The results of this study can provide reference for the preparation of polysaccharides from Sargassum fusiforme and studies on their prebiotic properties.

国家自然科学基金项目（31972011）；广州市国际合作项目（201907010035）