The Resistance Of Metal Resistance Essay

1630 Words Mar 27th, 2016 7 Pages
In microorganisms metal resistance character is regulated by genes which are organized in operons. Commonly, the heavy metal resistance genes are found on plasmid carried by metal resistant bacteria. In the presence of specific metals in the vicinity of bacterial niche the heavy metal resistance genes are expressed and induced. The regulation of expression of metal resistant gene is specific for each heavy metal and is dependent upon metal species concentration. The promoter and regulator genes of the bacterial operons responsible for resistance property and can be used to form metal-specific biosensors. Bacterial sensors which are metal specific coupled with tools for chemical analyses and can be used for differentiation of the concentration of bio-available metal from the total metal concentration of the samples (Turpeinen, 2002).
In case of Gram negative bacteria heavy-metal cations may react with glutathione and forms the bisglutathionato complexes and react with molecular oxygen to synthesize oxidized bisglutathione (GS-SG) (Kachur et al., 1998), metal cation and hydrogen peroxide (H2O2). In Gram negative bacteria cadmium is targeted on DsbA gene in the periplasm. DsbA gene is responsible for the formation of disulfide. Cadmium resistance in some gram-positive bacteria was also found to be mediated by CadA-like proteins (Liu et al., 1997). In S. cerevisiae, cadmium is bound by glutathione, and the resulting cadmium-bis-glutathione to complex is transported by an ABC…

Related Documents