Effect of extracellular polymeric substances (EPS) on Pb2+ accumulation byAureobasidium pullulans

In Pb2+ accumulation by Aureobasidium pullulans, the time to reach an equil ibrium state was not dependent on the initial cell dry weight. The Pb2+ acc umulation capacity was increased from 56.9 to 215.6 mg Pb2+/g cell dry weig ht as the biomass was stored from 1 to 53 days, and correlated with the amo unt of excreted extracellular polymeric substances (EPS). It was observed t hat Pb2+ accumulated only on the surface of the intact cells of A. pullulan s due to the existence of EPS, whereas Pb2+ penetrated into the inner cellu lar parts of the EPS-extracted cells.