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

Low-molecular-mass polysaccharides produced by Rhizobia strains may be comp osed of a mixture of cyclic (1-->2)-beta-D-glucans substitued by sn-1-phosp hoglycerol, succinic acid or methylmalonic acid or unsubstituted, and of ol igosaccharides produced de novo or by degradation of the high-molecular-mas s polysaccharides. The Sinorhizobium meliloti M5N1CS mutant strain (NCIMB 4 0472) produces unsubstituted cyclic glucans and these substituted by sn-1-p hosphoglycerol, a wide variety of oligoglucuronans and high-molecular-mass glucuronans partially acetylated at the C2 and/or the C3 position. Until no w, 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 membra nes for the separation of acetylated oligoglucuronans. Membranes with immob ilized histidine known for purification of proteins based on dipole interac tion were studied for the selective adsorption of glucuronans with discrimi nation of acetylation. (C) 1998 Elsevier Science B.V. All rights reserved.