Bioremediation

As bioremediation bioremediation or the use of living organisms ( prokaryotes, fungi or plants) for the biological detoxification of ecosystems is referred to, which are contaminated and polluted. The name is derived from the rare common word remedium for "cure".

Areas of application

The original applications for the bioremediation were primarily the remediation of contaminated sites to reduce by about spilled oil or waste dumps to clean radioactive waste. Important application areas are also the elimination of solvents, plastics and heavy metals and toxins such as DDT and dioxins. Bioremediation is a method that is used in the context of restoration measures.

Vascular plants

Some plants are able to accumulate under certain circumstances toxic metals such as zinc, nickel, lead or cadmium, at a considerable concentration in their tissues. This ability is interpreted as an adaptation to growth performance places on heavy metal containing soils. In the context of bioremediation these species can be consciously used in areas that have been contaminated, for example by mining or other anthropogenic activities with heavy metals and should be revegetated. If the exposed plant species are harvested after a certain time, the stored of them pollutants are removed from the ecosystem.

The mountain - Hellerkraut ( Thlapsi caerulescens ) is an example of a plant that can store large amounts of zinc, as well as the Haller foam cress (Arabidopsis halleri ). When Haller's foam cress zinc concentrations were observed approximately 1.5 % of the dry mass in measurements in the leaves. Compared to the memory ability of other metal- tolerant plants are also the same site the accumulation ability of Haller's foam cress was higher by more than 100 times. Nickel in high concentrations can save alyssum ( Alyssum ) in the leaves, some species of the genus. Measurements showed enrichments of more than 2 % of the dry mass. The American Curved pigweed ( Amaranthus retroflexus ) is able to store large amounts of cesium.

Weave

The lichen Trapelia involuta can colonize soils that are contaminated with uranium dust. This has been observed in soils that were contaminated with uranium dust as a result of mining activities. This lichen forms dark pigment, that has the ability to save uranium. Application possibilities, both for biological monitoring as well as possibly for a bioremediation.

Prokaryotes

The ecology has examined numerous prokaryotes for their ability to contribute to the bioremediation of soils or waters. In order to gain insights here, the genomes of about seven Prokaryontenarten decrypted to this question position. In the bacterium Shewanella oneidensis was for example found that it can convert soluble uranium, chromium and nitrogen soluble to insoluble forms. The advantage is seen in that the insoluble substances may be less easily washed and it provides a better ground and is given watercourse protection.

Biotechnology

Biotechnology also is investigating how they can improve the performance of organisms, which are used for bioremediation using biotechnological methods.

Using genetic engineering techniques, the range of options was further expanded. Today it is approximately possible to introduce genes of difficult to cultivate bacteria in other bacteria and thus to exploit the positive features of the newly created organisms. In order to control them, they also genes are implanted that make them dependent on the supply of certain substances, so that they die without them. Were also, for example, Genes for phosphors implanted to the mark. The modified strains, usually abbreviated GEMs referred to as "genetic engineered microorganisms ". GEMs are used for various application areas such as Contamination with oil, degradation of aromatic compounds have been developed in conditions of oxygen deficiency or heavy metals. The use of GEMs will widely criticized. The main criticism is that released bacteria strains are no longer controlled or retrievable and properties of the novel strains could be transferred by horizontal gene transfer to other strains. The high expectations of the technical benefits have not been confirmed in many application examples. An insert in the open field, the going beyond field trials carried out so far.