MICROORGANISMS FOR BIOREMEDIATION OF HEAVY METALS
Introduction Bioremediation refers to the use of microorganisms to degrade contaminants that pose environmental and human risks. Bioremedition processes typically involve the actions of many different microbes acting in parallel or sequence to complete the degradation process [1]. Trace elements or trace metals are elements that are present at low concentrations in rocks, soils, water and in the atmosphere. Some of them (for example, cobalt, copper, zinc, nickel or molybdenum) are nutrients, but a variety of them, when they are at high concentrations, are toxic to living beings. Some of these toxic elements are sufficiently volatile because their atmospheric transport is significant and can therefore be a danger to the environment. Among them are mercury, lead, arsenic, cadmium and selenium. Many of these trace elements lead to oxidoreduction reactions catalysed by microorganisms, and some can also be found forming organic compounds derived from microbial action. Microorgani...