超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺优化

Optimization of purification procedure for capsular polysaccharide hydrolyzate of Neisseria meningitidis group C by ultrafiltration

目的优化超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺。方法以截留分子量为300 000的超滤膜对C群脑膜炎球菌荚膜多糖降解物进行超滤分离,以膜通量和多糖回收率为评价指标,优化方法中的超滤膜材质(300 k Da的聚醚砜膜和再生纤维素复合膜)、透析次数(1~6次)、超滤缓冲液(0.15 mol/L Na Cl、0.5 mol/L Na Cl、50 mmol/L的PBS和H2O)、多糖初始溶解浓度(0.25、0.5和1 mg/m L)和超滤方式(浓缩补液超滤和恒体积超滤)。采用最佳条件对C群脑膜炎球菌荚膜多糖降解物进行检测。结果 C群脑膜炎球菌荚膜多糖降解物的最佳超滤条件为:以再生纤维素复合膜为超滤膜,0.15 mol/L Na Cl为超滤缓冲液,透析次数为5次,多糖初始溶解浓度为1.0 mg/m L,超滤方式为浓缩超滤。该方法可有效去除C群脑膜炎球菌荚膜多糖降解物中较大分子量的多糖组分,多糖回收率在80%以上,且可在一定程度上降低多糖水解物的内毒素含量。结论成功优化了超滤法纯化C群脑膜炎球菌荚膜多糖降解物的工艺,显著提高了工作效率。

Objective To optimize the purification process for capsular polysaccharide hydrolyzate of Neisseria meningitidis group C by ultrafiltration. Methods The capsular polysaccharide hydrolyzate of N. meningitidis group C was purified by ultrafiltration using the ultrafiltration membrane with relative molecular mass cutoff of 300 000. The ultrafiltration membrane material（300 k Da polyethersulfone membrane and regenerated cellulose composite membrane）,times of dialysis（1 - 6）,ultrafiltration buffer（0. 15 mol/L sodium chloride,0. 5 mol/L sodium chloride,50 mmol/L PBS and water）,initial liquid concentration of polysaccharide（0. 25,0. 5 and 1 mg/m L） and ultrafiltration method（concentrated ultrafiltration and constant volume ultrafiltration）were optimized using membrane flux and polysaccharide recovery rate as evaluation indexes. The hydrolyzate purified under the optimal condition was tested. Results The optimal ultrafiltration membrane, ultrafiltration buffer, time of dialysis, initial liquid concentration of polysaccharide and ultrafiltration method for hydrolyzate of capsular polysaccharides of N. meningitidis group C were regenerated cellulose composite membrane,0. 15 mol/L sodium chloride,5 times,1. 0 mg/m L and concentrated ultrafiltration respectively.Under this condition,the polysaccharide components with high relative molecular masses were effectively removed,while the polysaccharide recovery rate was more than 80%,and the polysaccharide hydrolyzate endotoxin content decreased to a certain extent. Conclusion The purification procedure for capsular polysaccharide hydrolyzate of N. meningitidis group C was successfully optimized,which significantly improved the working efficiency.