针对纳滤膜深度纯化普鲁兰多糖的进水要求,试验采用混凝-活性碳吸附-超滤膜工艺预处理普鲁兰多糖发酵液。试验结果表明:最适混凝剂用量为10 g/L,最适活性碳用量为25 g/L,脱色时间为65 min;超滤膜分子截留量为67 kDa,最佳的超滤操作压力0.08 MPa,pH3.5,温度为25℃。发酵液浓度可从10 g/L浓缩至27 g/L,且多糖的回收率达到85%以上。

In order to meet the requirement of nano-filtration membrane,a integrated process consisting of coagulate-activated charcoal-ultrafiltration( UF) was proposed to treat pullulan fermentation broth. The results demonstrated that the optimum dosage of coagulate was 10 g /L and the optimum dosage of activated charcoalwas was 25 g /L,the decoloration time was 65min. In the experiment,the polysulfone ultrafiltration membrane with molecular weight cut-off67 kDa had a better effect on concentrating pullulan. The optimum technological parameters of polysulfone ultrafiltration were: the operation pressure 0. 08 MPa and the temperature of fermentation broth 298. 15k,the pH of fermentation broth 3. 5. The concentration of fermentation broth was from 10 g /L to 27 g /L and the recovery rate of pullulan was up to 85%.