低酰基结冷胶提取工艺研究

Study on extraction method of deacetylated gellan gum

目的:针对高粘度结冷胶发酵液,发展低酰基结冷胶提取工艺。方法:将浓度为16.5g/L的结冷胶发酵液pH调至10,于80℃下保温20min,得低酰基结冷胶料液。料液经CaCl2絮凝菌体后用板框过滤除菌,滤液稀释6倍,加入碱性蛋白酶除蛋白,然后超滤浓缩4倍,再用活性炭脱色,最后用乙醇沉淀出结冷胶并干燥。结果:结冷胶回收率达76%,平均分子量为79万,透光率为86%,凝胶强度为890g/cm2。结论:使用该工艺提取低酰基结冷胶是可行的,产品质量符合相关标准。

Objective： Develop a method for extracting deacetylated gellan gum from high viscosity broth. Method： Keep fermentation broth at 80℃,pH10 for 20min to make gellan gum deacetylated. Then add CaCl2 to flocculate cells,and the solution was filtrated to remove cell mass. After cell removing,the solution was diluted and alkaline protease was added to remove protein. Then concentrate the solution with ultrafiltration and remove the pigment using active carbon. At last deposit the gellan gum with alcohol,after drying the refined product was made. Result： The total recovery,molecular weight,transparency,gel strength of deacetylated gellan gum was 76%, 790 000,86% ,890g/cm2 respectively. Conclusion： The method was feasible for extracting deacetylated gellan gum ,and the product is in accordance with related standard.