Cr(VI) sorption by intact and dehydrated Candida utilis cells:: differences in mechanisms

The Cr(VI) sorption kinetics by intact and dehydrated Candida utilis cells were studied. Yeast dehydration led to enhanced Cr(VI) sorption activity by cells during the first 15-20 min of rehydration. In experiments with K2Cr2O7 as a chromium source, [Cr2O7](2-) was converted into [CrO4](2-) during incubation with dehydrated biomass. An effect of the considerably enhanced Cr(VI) sorption activity by dehydrated cells in the buffered media at pH approximate to 8.0 can serve as another confirmation of the different sorption mechanisms of intact and dehydrated C.utilis cells. This effect was not revealed in water solution at pH 8.0. This phenomenon will be studied in further investigations. (C) 2001 Elsevier Science Ltd. All rights reserved.