超滤分离蝙蝠蛾拟青霉胞外多糖工艺优化

Process Optimization of Exopolysaccharides from the Fermentation Broth of Paecilomyces hepiali by Ultrafiltration

为获得超滤膜法分离蝙蝠蛾拟青霉发酵液中胞外多糖的工艺参数,采用切向流超滤比较不同膜组件对该胞外多糖的截留率。结果表明：分别采用0.1μm和100 ku膜组件进行分离,可将发酵液中胞外多糖分为分子质量〉2 000 ku,100~2 000 ku和〈100 ku 3部分;通过单因子和正交试验对100 ku膜组件的操作参数如料液比、操作压力、p H进行了优化,得出该膜组件的最佳操作参数为料水比3：2,操作压力0.2 MPa和p H 8.5。在此条件下,膜通量和多糖截留量分别达到19.5 L·m2·h-1和122.47 g·m2·h-1,损失率为2.58%。经HPLC检测,截留液中800 ku多糖组分的纯度达89.7%。与传统的分离方法相比,超滤膜法分离发酵液中胞外多糖具有快速、能耗低和损失率低等优点。

In order to acquire the technological parameters of ultrafihration membrane separation exopolysaccharide from the fermentation broth of Paecilomyces hepiali. In this study, the trapping effects of membranes of different molecular weight cut-off with the tangential flow ultrafiltration system were compared. The results showed that the exopolysaccharide in the fermentation broth can be divided into three segments （〉2000 ku, 100-2 000 ku and 〈100 ku） when using the membrane of 0.1 μm and 100 ku in order. Furthermore, the effect of material to water, operation pressure and pH on membrane flux were tested using 100 ku membrane module by one-actor-at-a-time and orthogonal design. The optimal operation conditions were material to water 3：2, 0.2 MPa pressure and pH 8.5, and the membrane flux and trapped polysaceharide were 19.5 L·m^2·h^-1 and 122.47 g·m^2·h^-1. In the trapped fluid the purity of 800 ku polysaccharide fraction was 89.7%. Compared with the traditional separation method, ultrafiltration by membrane possessing a series ad- vantage of lower energy expenditure, loss percentage and higer performance.