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

Structural Changes in the Perovskitic Compounds Series Sr2Mg1-xMIIxMoO6

Two series of perovskite type compounds (Sr2Mg1-xZnxMoO6 and Sr2Mg1-xNixMoO6) are characterized from the structural point of view. The synthesis conditions are briefly described. The cation distribution of the two series compounds were determined by X-ray diffraction