Activity of exoglycans as sorbents of heavy metal ions

: The ability of yeast exoglycans (from Cryptococcus laurentii, Cr. luteolus, and Sporobolomyces albo-rubescens) to absorb copper and lead ions has been studied. The sorption isotherms have been obtained, which indicates that the mechanism of interactions in the system polysaccharide-metal is complex. For the majority of the glycans, the absorption selectivity was considerably higher in the case of copper, as compared to lead. The observed discrepancy in the effects of pH and temperature on the absorption indicates that the bonds mediating ion absorption by glycans are of different nature. In conclusion, yeast exoglycans are efficient sorbents of copper and lead ions, and lutelan is the most active exoglycan in this respect.