Separation of low-molecular-mass acetylated glucuronans on l-histidine immobilized onto poly(ethylene–vinyl alcohol) hollow-fiber membranes

Abstract

Low-molecular-mass polysaccharides produced by Rhizobia strains may be composed of a mixture of cyclic (1→2)-β- d-glucans substitued by sn-1-phosphoglycerol, succinic acid or methylmalonic acid or unsubstituted, and of oligosaccharides produced de novo or by degradation of the high-molecular-mass polysaccharides. The Sinorhizobium meliloti M5N1CS mutant strain (NCIMB 40472) produces unsubstituted cyclic glucans and these substituted by sn-1-phosphoglycerol, a wide variety of oligoglucuronans and high-molecular-mass glucuronans partially acetylated at the C2 and/or the C3 position. Until now, the purification of oligoglucuronans with a specific acetylation degree was not possible. In this work, we have studied the possibility of using l-histidine immobilized onto poly(ethylene–vinyl alcohol) hollow-fiber membranes for the separation of acetylated oligoglucuronans. Membranes with immobilized histidine known for purification of proteins based on dipole interaction were studied for the selective adsorption of glucuronans with discrimination of acetylation.