中文摘要：

选取了自养小球藻（Chlorellaautotrophica）为研究对象，以超声辅助提取法进行硫酸多糖提取，所得粗多糖采用凝胶法在AKTA系统下进行分离纯化得到PCA2-1及PCA2-2共2种硫酸多糖，电泳及HPGFC法检验结果表明所得硫酸多糖的均为均一多糖。选取了4种在海洋环境或医学中常见的菌株为作为受试菌株，分别进行了PCA2-1和PCA2-2抑菌活性的初步实验，其中大肠杆菌抗生素检定株（Escherichiacoli）和解藻朊酸弧菌（Vibrioalginomicus）为革兰氏阴性菌，表皮葡萄球菌（Staphylococcusepidermidis）和溶壁微球菌（Micrococcus船odeikticus）为革兰氏阳性菌。所得结果表明，这2种多糖均对某种特定的菌株表现出一定的抑制作用。其中，PCA2-2对溶壁微球菌和解藻朊酸弧菌有较强有抑菌作用，KI值可达70％以上。

英文摘要：

Polysaccharides from Chlorella autotrophica are extracted with ultrasonic assistant method in the study. AKTA purifier system is applied in the isolation,and we obtain two polysaccharides,PCA2-1 and PCA2-2,both of which are verified to be homologous by electrophoresis and HPGFC. Antibacterial experiments of PCA2-1 and PCA2-2 are carried out and the bacteria that are common in marine environment and medicine are selected,including Escherichia coli （G^-）, Vibrio alginolyticus（G^-）,Staphylococcus epidermidis（G^＋） and Micrococcus lysodeikticus （G^＋）. Results show that the two polysaccharides can inhibit some specific bacterium to some extent. PCA2-2 has a steady and intensive effect on Micrococcus lysodeikticus and Vibrio alginolyticus and the killing index （KI） exceeds 70%.