METHOD FOR UTILIZING AN EXOCELLULAR POLYSACCHARIDE ISOLATED FROM ZOOGLOEA RAMIGERA

摘要

A method of using a purified exocellular polysaccharide, Zooglan produced by Zoogloea ramigera, such as a viscosity modifier, a gelling agent, a tension reducing agent, a dispersing agent, a flocculating agent, or an emulsifying agent, the properties of the pH-dependent polymer, the polymer concentration, the ionic strength of the solution and processing parameters such as the mechanical shear, said polymer properties that can be modified by varying these values. The overall conformation of Zooglan, which is responsible for its functional properties, can be manipulated with the pH and / or ionic strength of the solution. For example, the intrinsic viscosity of Zooglan (estimated molecular weight = 2 x 107) can vary between 16 and 170 dl / g in an aqueous solution according to a pH between 2 and 9 and a salt concentration between 0 and 1 M KCl . The Zooglan is a polyelectrolyte above pH 2. The chain Zooglan is relatively stiff with a stiffness parameter equal to 0.02. Zooglan solutions at a concentration greater than 0.01 g / dl are viscoelastic and pseudoplastic thixotropic with a hysteresis and a critical yield stress. The effects of shear rate and the shearing time on viscosity of Zooglan solutions are recoverable or not depending on the conditions of the solution. The Zooglan can form a gel network or by entanglement of the chain. This wide variety of functional properties makes Zooglan effective molecule for use in many products such as pharmaceuticals, cosmetics and body care, food products, textiles, paints, inks and paper.