Klebsiella sp.LDX1-1多糖的发酵影响因素和絮凝特征

Influencing factors of fermentation and flocculation characteristics of Klebsiella sp. LDX1-1 polysaccharide

Klebsiella sp.LDX1-1多糖产生的最佳碳源为麦芽糖与低聚异麦芽糖的混合糖,其中低聚异麦芽糖质量分数为8%;最佳氮源为2 g/L的NH4NO3。2 g/L的雪松松针提取物、0.4%的曲拉通X-100显著促进多糖合成,产量分别提高12.46%和14.38%。用综合试验因素进行发酵,得到的最适发酵周期为24 h,粗多糖产量达到23.46 g/L,比发酵基础培养基条件下提高43.14%。由发酵液制取的初步纯化多糖具有高效絮凝活性,对高岭土悬液和黄河水的絮凝率分别是98.43%和96.31%。纯化样品的红外光谱定性分析表明:发酵产生的黏性物质成分为典型的生物多糖。

The best carbon source for the production of Klebsiella sp.LDX1-1 polysaccharide is the mixture of maltose and isomaltooligosaccharide,in which the mass fraction of isomaltooligosaccharide is 8%,and the best nitrogen source is NH4NO3 for 2 g/L.2 g/L of cedar needle extract and 0.4%of Triton X-100 significantly promote the polysaccharide synthesis,and the yield increased by 12.46%and 14.38%,respectively.The optimum fermentation period is 24 h,and the yield of crude polysaccharide is 23.46 g/L,which is 43.14%higher than that under the basic fermentation conditions.The preliminary purified polysaccharide prepared from fermentation broth has high flocculation activity,and the flocculation rate of kaolin suspension and the Yellow River water is 98.43%and 96.31%,respectively.The qualitative analysis of the purified samples by infrared spectroscopy shows that the components of the viscous substances produced by fermentation are typical biological polysaccharides.