PROCESS FOR THE RECOVERY OF L-FUCOSE FROM EXOPOLYSACCHARIDES

摘要

The present invention relates to the isolation, on an industrial scale, of L-Fucose (or 6-Deoxygalactose) from exopolysaccharides obtained by fermentative process. The purification step is a crucial point of the L-Fucose recovery process: the polysaccharide is recovered by ultrafiltration in that it quantitatively remains in the retentate together with only the cells of the microorganism while all the culture medium residues, the fermentation by-products and the salts are eliminated in the permeate in an almost quantitative manner. This step excellently resolves the problem of the purification of the Fucose with a view to obtaining a high-purity crystal; it indeed allows separation of the sugars that make up the polysaccharide from all those by-products having a low molecular weight that cannot be eliminated in the subsequent steps and which, being present in considerable amounts, constitute a great problem for the direct crystallization of the product of the product.