Two-Component Systems in the Regulation of Heavy Metal Resistance

摘要: Microbial resistance to heavy metals is widespread. This not surprising, as early in evolutionary history microorganisms would have been contact with toxic concentrations of metals. Geochemical events caused the release from earth’s crust into biosphere, and still do. The change an anoxic oxic biosphere altered redox state biological availability a number Resistances wide range metal ions reported bacteria. These include resistances that are purely toxic, no ascribed function (such mercury cadmium), excess but required small amounts for correct functioning bacterial cell copper zinc) (Silver Ji 1994; Silver Walderhaug 1992). Bacteria, other unicellular organisms, must mechanisms which allow them avoid toxicity, yet accumulate enough essential normal growth.