隐球菌荚膜多糖GXM纯化方法的改良研究

Improvement of the purification method of cryptococcal capsular polysaccharide glucuronoxylomannan

目的对采用乙醇和十六烷基三甲基溴化铵(CTAB)特异性沉淀和纯化葡萄糖醛酸木糖甘露聚糖(GXM)的传统方法进行针对性改良,探索一个过程简单、耗时少、效率高的GXM纯化方法。方法250 mL的H99和R265增菌液分别以乙醇和十六烷基三甲基溴化铵(CTAB)特异性沉淀得到GXM-CTAB复合物。采用24∶1氯仿:异戊醇混合液分离GXM-CTAB复合物,再加入3倍体积的异丙醇沉淀析出GXM。结果采用GXM改良纯化法从250 mL增菌液中分别获得了约7.8 mg和18 mg的H99GXM和R265GXM,H99GXM和R265GXM获得率(GXM/GXM和GalXM混合多糖)分别为39%(7.8/20)和45%(18/40)。此外,传统的GXM整个纯化过程需耗时2周,而改良方法耗时8 d。结论本研究采用的GXM改良纯化法不仅与传统方法的提取效率相当,并且纯化耗时减少,提取过程更加简单。

Objective To explore a simpler,less time-consuming,and more efficient glucuronoxylomannan(GXM)purification method compared with the traditional one which adapts ethanol and cetyltrimethylammonium bromide(CTAB)to specifically precipitate and purify GXM.Methods The GXM-CTAB complex was obtained by specifically precipitating 250 mL of H99 and R265 cultures with ethanol and CTAB.Then,the GXM-CTAB complex was separated using a 24:1 chloroform:isoamyl alcohol mixture.Next,GXM was precipitated by adding 3 volumes of isopropanol.Results About 7.8 mg and 18 mg of H99GXM and R265GXM were respectively obtained from 250 mL of the culture using the GXM modified purification method.The acquisition rates(GXM/GXM and GalXM mixed polysaccharides)were 39%(7.8/20)and 45%(18/40),respectively.In addition,the traditional GXM purification process takes a total of 2 weeks while the modified method only takes 8 days.Conclusion The GXM modification purification method used in this study is comparable to the extraction efficiency of the traditional method,also the purification time is shortened and the extraction process is simpler.