Optimizing The Growth Condition And Studying The Active Constituents Of Nostoc Flagelliforme Cells

Nostoc flagelliforme is a terrestrial cyanobactrium that is distributed on thedesert region of arid or semiarid. In order to resume the limited biologicalresources of N. flagelliforme and study the active constituents, taking liquidculture of N. flagelliforme cells as the inoculum source and culture them on threedifferent solid matrix.Adding three different hydrophilic extracellularpolysaccharides to regulate wetting conditions of solid material for water andmake N. flagelliforme growing better. The modification process, purificationprocesses and chemical structure of N. flagelliforme polysaccharides werepreliminarily studied, and also study the extraction process of Phycocyanin andthe activity of sulfated polysaccharides. The extraction process and activity assayon the enzyme of production polysaccharides of N. flagelliforme cells wasstudied preliminarily.The main results are as follows:First, the biomass of N. flagelliforme was improved by adding hydrophilicpectin, sodium alginate and gum arablc.Adding pectin was best in favor of thegrowth of N. flagelliforme cells, sodium alginate was second and the gum arablchaving the minimal effect. In addition, the addition dosage of polysaccharide wasnot the more the better.0.3%of the polysaccharide dosage was the mostappropriation, and the biomass of N. flagelliforme cells would reduce when thedosage was more than0.3%.Second, the best sulfated method and the most appropriate solvent weredetermined through the deteminition of DS.The best sulfation process forextracellular polysaccharides was: sulfation time3h,extraction temperature60℃,molar ratio1:2.5, solvent volume1:40. The best sulfation process for capsularpolysaccharides was: sulfation time2h,extraction temperature60℃, molar ratio1:2.5, solvent volume1:40.Third, the sulfatied exopolysaccharide and capsularpo1ysaccharide of N.flagelliforme were purified by DEAE-52cellulose column chromatography and Sephadex G-100column.The N. flagelliforme polysaccharides were sulfatiedsuccessfully by the results of spectroscopy and infrared spectroscopy.Theantioxidant capacity of sulfatied polysaccharides were studied. The N.flagelliforme polysaccharides and the sulfatied polysaccharides both havescavenging ability on PPPH radical, OH radical and O-2radical. The scavengingeffect on the three radical was positively related to the polysaccharidesconcentration within a certain concentration range. The antioxidant capacity ofsulfatied polysaccharides were better than the non-sulfatied.Fourth, the best extraction method on phycocyanin were:liquid to solid ratio172:1(mL:g),ultrasonic power540W,ultrasonic time11min.Fifth, the extraction process and activity assay on the enzyme of productionpolysaccharides of N. flagelliforme cells were studied preliminarily.The resultsshowed that the enzyme of production polysaccharide in the N. flagelliformecells had a certain biological activity.