Study On The Purification And Structure Of Polysaccharides From Nostoc Flagelliforme

The effect of the four different DEAE ion-exchange resins on the purification of extracellular polysaccharide from Noscoc flagelliforme were compared. And than the effects of different types of DEAE cellulose resin on the separation efficiency were conducted. The structure of N. flagelliforme polysaccharide were studied using enzymatic hydrolysis, periodate oxidation, Congo red, element analyse and scanning electron microscopy (SEM). The results were as follows:(1) Study on the purification of polysaccharide from Noscoc flagelliforme with four different ion-exchange resins. Under the same elution condition, the curves with DEAE-Cellulose ion-exchange resins is the best. The purities of polysaccharides are improved from31.9%to80.0%. The proten contents are reduce to1.938μg/mL. It can be concluded that DEAE-Cellulose is the best ion-exchange resin for purifying polysaccharide from Noscoc flagelliforme.(2) Effects of the different types of DEAE cellulose resin, elution regents and elution methods on the purification of extracellular polysaccharides of Nostoc. The effects of OH" DEAE cellulose resin on the separation efficiency is better than Cl" resin. NaCl is best elution regent. The optimal elution concentration is0.2mol/L NaCl.(3) The condition of extraction and purification of N. flagelliforme polysaccharide. The column of ion-exchange chromatography (03.5x60) was packed with DEAE-Cellulose anion ion-exchange resin solutions. The concentration of sample was l.Omg/mL. The polysaccharide was eluted by0.2mol/LNaCl at a flow rate of lmL/min.(4) Structure analyse polysaccharide of Noscoc flagelliforme. The polysaccharide form ordered multiple helical structure, which has β-(1â†'4) glycosidic bond。 The AFM images showed that both polysaccharides twisted each other formed hemispheroid structures, with the thicknes1.0-15.Onm and diameter50-200nm.This study afforded the basic data for extraction and purification of N. flagelliforme polysaccharide. It provides theoretical foundation for industrialization of extraction and isolation from N. flagelliforme cells cultures. And than the study on primary structureafforded the basic data for the furthermore research on advanced structure and the relationship between structure and active.