Jornal de Biorremediação e Biodegradação

Abstrato

Potential Application of Modified Saccharomyces Cerevisiae for RemovingLead and Cadmium

Lívia de CF, Mario HB and Benedito C

Recently, heavy metal pollution has become a worldwide concern. Saccharomyces cerevisiae have been used for bioremediation process for heavy metal uptake. In this study, S. cerevisiae was genetically modified with the gene EC20 (synthetic phytochelatin) with the purpose to enhance the accumulation capability for Lead (Pb2+) and Cadmium (Cd2+). S. cerevisiae has showed high biosorption capability of Pb2+, followed by Cd2+. Indeed, the transformed cells exhibited even higher capacity to accumulate lead. TEM (transmission electronic microscopy) images of transformed S. cerevisiae showed accumulation of heavy metals on cell wall, which was also verified by EDS (energy dispersive spectrum). There are many mechanisms involved in metal uptake and for some unknown reason. The results of yeast expressing EC20 were better detected when yeast cells were grown in the presence of Pb2+ than with Cd2+, as clearly observed with the improvement in Pb2+ retention by yeast cell wall.