Structural and Characteristics of Exopolysaccharide Produced by Alcaligenes sp.NX-3 / 微生物学通报

ABSTRACT

The structure and characteristics of the soluble exopolysaccharide(PS-238) produced by Alcaligenes sp.NX-3 were studied.The analytic sample was prepared by ethanol precipitation then proteins were removed by the Sevag method.The components of polysaccharide were identified by TLC、 GC and chemical method after acid hydrolysis as glucose,mannose,rhamnose and glucuronic acid.By means of IR and periodate oxidation,it showed that the polysaccharide was mainly consisting of(1→3)and(1→4) glucosidic linkages.The relation between viscosity and shear rate、concentration、temperature、pH and salts was investigated.The results showed that the solution of PS-238 is a typical pseudoplastic liquid,having high viscosity at low concentrations.The viscosity of 1%PS-238 water solution could reach 3300cp at 25℃.It has the excellent stability towards pH2~13,also has outstanding property of viscosity retention even at temperatures up to 150℃.Some kinds of salts were cooperated with PS-238 as a thickening agent.