Extracellular K5 polysaccharidic antigen recovery performed by different cell separation technologies

The K5 polysaccharidic antigen obtainable from a strain of Escherichia coil is the non-sulphated precursor in heparin biosynthesis; K5 is composed by two components, 16000 and 1500 Da, their ratio depending on the fermentatio n conditions. In this study an assessment was made of how various cell-cult ure filtrate separation technologies affected the components themselves and their ratio. A dynamic membrane filtration technology a tubular ceramic mo dule for tangential flow microfiltration and the standard discontinuous cen trifugation were comparatively employed to perform the separation. Experime nts carried out on E. coli cultures containing the two components in differ ent ratios showed that the DMF system is a suitable technology for K5 isola tion.