Saccharomyces cerevisiae as uranium bioaccumulating material: the influence of contact time, pH and anion nature

The possibility of bioaccumulation of uranium species in beer yeast was investigated. The behaviour of the Saccharomyces cerevisiae–UO2 2+ system was studied vs. contact time, pH and anion nature with no ionic competition. Analysis of the data revealed the following optimal working conditions: contact time = 1 h, pH = 6.5 and 10-1 M UO2(CH3COO)2 solution as uranyl source; as a result, the maximum degree of bioaccumulation attends a value nearly 8.75 mmol UO2 2+/g yeast. Both, a scanning electron microscope (SEM) and amino acid determinations lead to the conclusion that the uranyl nitrate solution may devastate the yeast cells provoking membrane damage and the release of the cell constituents (including the bioaccumulated uranium species). The results suggest the possible use of Saccharomyces cerevisiae as a biological decontaminant of uranium containing wastewaters

Removal of uranyl ions from residual waters using some algae types

This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillinium sp, as well as the Glucide extract of Porphyridium cruentum, under various experimental conditions. The retaining degree of the bioaccumulated uranyl ions, as well as the leaching degree, in HCl and H2O media, of the same ions previously retained on algae were established. The retaining degree decreases in the eerie: Scenedesmus quadricauda >Anabaena karakumica > Penicillinium sp > Calothrix brevissima. The leaching effect of bioaccumulated uranyl ions is higher in hydrochloric acid than in water