槲蕨多糖的提取工艺优化及其抑菌性研究

Studies on the extraction optimization of polysaccharide from Drynaria fortunei and its antibacterial activities

以槲蕨块茎为材料,采用水提醇沉法提取槲蕨多糖。在单因素考察的基础上,以多糖的得率为响应值,料液比、提取温度、提取时间为自变量,建立数学模型,利用响应面法获得槲蕨多糖的最佳提取工艺。采用纸片扩散法比较了不同浓度多糖的抑菌效果。结果表明：槲蕨多糖最佳提取工艺条件为：料液比1∶25,提取时间2.0 h,提取温度为85℃,在此优化条件下多糖得率为7.57%,与响应面分析预测值7.61%基本相符。槲蕨多糖对杆菌有明显的抑制作用,对供试球菌无明显抑制效果,多糖最低抑菌浓度为10 mg/m L。

The polysaccharides from tuber of Drynaria fortunei were extracted by water-extraction and alcohol-precipitation method. Based on single factor experiments and the yield of extracted polysaccharides,the solid to liquid ratio,extraction temperature and extraction time as the independent variables,the mathematical model was set up,and the response surface method was employed to explore the optimal extractable conditions of polysaccharides. Meanwhile,the antibacterial activities of polysaccharides were also examined by disk diffusion method. The results showed that the optimal extractable conditions were as follows：solid to liquid ratio 1∶25（g∶m L）,extraction temperature 85 ℃,extraction time 2.0 hours. An experimental polysaccharide yield of 7.57% was obtained under these conditions,which was basically consistent with the model predicted value of 7.61%. The polysaccharides could inhibit markedly bacilli,but had no influence on cocci,and the minimum inhibitory concentration of polysaccharides was 10 mg/m L.