In quimioadsorció a product of the metabolism of bacteria osmosis is expelled, forming osmosis a pr

Gerard Funosas, Furriols Henry, Marc and George Fusellas Galiano Removal of metals by microorganisms is based on the metabolism of these bacteria use to transform metal and it could more easily extract the environment, and is therefore a type bioremediation. Due to the variety osmosis show that metabolic groups procaritoes find species that can carry out reactions ivseres to collect much of this metal in solution that are wrongly environment and want to remove, sometimes in extreme conditions of pH or temperature. That's why bioremediation by microorganisms is a very viable and environmentally sustainable solution to clean areas contaminated water or accumulations of metals, especially heavy, which unfortunately gives very industry or mining, osmosis for example.
Microorganisms have several ways to use and transform metal, and therefore it is necessary to know its metabolism to use it in our favor. All these physiological processes outlined below are summarized in the diagram in Figure 1. - Biotransformations These processes cause a chemical change osmosis on the metal, ie a reduction or oxidation of the metal. These transformations can give little osmosis water-soluble compounds, or volatile compounds. Depending on the stage of oxidation where it is a metal species and transforming a microorganism can carry out two possible transformations: osmosis Leaching: Step-insoluble solid state to a state in aqueous osmosis phase. It's basically a process of oxidation. Widely used in the mining industry. Immobilization: Step one was soluble in the aqueous phase to a solid phase of insoluble osmosis (pellet). I t basically a process osmosis of reduction. Widely used in the purification of water contaminated by metals. - Biosorció is that organisms biosorbents (isolated from contaminated ecosystems) retain metals during relatively short time intervals when in contact with solutions of these metals. This micro lot cheaper bioremediation projects. - Biomineralization Many microorganisms are able to precipitate osmosis metals as hydroxides or carbonates through a resistance mechanism encoded by a gene located on the plasmid. This mechanism is based on the secretion of toxic metals in the cytoplasm to the cell exterior via a proton pump contragradient. This causes an alkalinization of the external cell surface and therefore the precipitation of heavy metal cations.
This mechanism consists of a cellular membrane transport system which incorporates metal bacteria present in the cellular environment, a process that involves expenditure of energy. Once the metal is in the cytoplasm, it is hijacked by a protein-rich sulfide groups. Other eukaryotes can do to accumulate them vacuole. Some examples of bioaccumulation of great interest to man is Pseudomonas aeruginosa.
In quimioadsorció a product of the metabolism of bacteria osmosis is expelled, forming osmosis a primary tank once a metal is associated with the environment, forming a nucleus of crystallization in which the ionic compound accumulates easily osmosis ejectable. An example of this is the operation of sulfur reducing bacteria.
Microorganisms oxidizing iron and manganese bacteria called Iron defined as a group of aerobic osmosis bacteria using oxidation of ferrous ions and / or manganosos as a main part of their metabolism. It is a very heterogeneous and includes morfoolgies in some cases as Gallionella or filamentous bacteria Sphaerotilus. The process is based on using ferric ions dissolved in the medium as a source of electrons, oxidizing them usually in the form of hydroxide, thus forming an insoluble compound precipitated. Apart from that many of these bacteria have the ability osmosis to produce extracellular polysaccharide mucilaginós and adhesive. This substance coats the outer surface of the cell wall and is used for the accumulation of ferric hydroxide precipitate. That is why these bacteria in natural environments reddish or ocher-colored. Oxidation in respiration
Figure 3: Gallionella ferruginea Source: http://microbewiki.kenyon.edu/ index.php / Gallionella The oxidation of iron occurs naturally at neutral pH and aerobic conditions, leaving the bacteria use it as a source of electron, whereas in acid pH Fe 2 + is more stable, allowing the bacteria to oxidize it to Fe 3 +. So most of the iron oxidizing bacteria are acidophilic. However there are some oxidizing bacteria of faith