Bioremediation

As bioremediation or bioremediation , the use of organisms (will prokaryotes , fungi or plants ) for biological decontamination of ecosystems called, the contaminated with pollutants are loaded. The name is derived from the rarely used word "remedium" for remedies .

Areas of application

The original areas of application for bioremediation were above all the remediation of contaminated sites , for example to break down spilled oil or to clean tailings with radioactive waste. Other important areas of application are the removal of solvents , plastics and heavy metals as well as toxins such as DDT and dioxins . Bioremediation is a method that is used in the context of renaturation measures .

Vascular plants

→ Main article phytoremediation

Some types of plants, so-called hyperaccumulator plants , are able to accumulate toxic metals such as zinc , nickel , lead or cadmium in their tissues in considerable concentrations. This ability is interpreted as an adaptation performance to growth locations on heavy metal-containing soils. In the context of biological remediation, these species can be used deliberately in areas that have been contaminated with heavy metals , for example through mining or other anthropogenic activities, and are to be recultivated. When the exposed plant species are harvested after a certain period of time, the pollutants they store are also removed from the ecosystem. Enriching the effectiveness of the hyperaccumulators minerals has opened a new branch of industry, phytomining. Hyperaccumulators are cultivated specifically for the extraction of minerals on soils with a high metal concentration. After the plant has been harvested, dried and burned, the minerals are chemically removed from the ashes of the plant and processed for further use in industry.

The mountain light herb ( Thlapsi caerulescens ) is an example of a plant species that can store zinc to a high degree, as is Haller's cress ( Arabidopsis halleri ). In the case of Haller's cress, zinc concentrations of around 1.5% of the dry mass were found in measurements. Compared to the storage capacity of other similarly metal-tolerant plants in the same location, the accumulation capacity of Haller's cress was more than 100 times higher. Nickel in high concentrations can store some species of the genus stone herb ( Alyssum ) in the leaves. Measurements showed accumulations of more than 2% of the dry matter. The American crooked foxtail ( Amaranthus retroflexus ) is able to store large amounts of cesium .

weave

The lichen species Trapelia involuta can colonize soils that are contaminated with uranium dust . This was observed in soils that were contaminated with uranium dust as a result of mining activities. This type of lichen forms dark pigment that has the ability to store uranium. Possible uses arise both for biological monitoring and possibly for biological remediation.

Mushrooms

The white rot is examined for the bioremediation of organic substances.

Prokaryotes

Ecology has examined numerous prokaryotes for their ability to contribute to the biological remediation of soils or bodies of water. In order to gain knowledge here, the genomes of about seven prokaryote species were deciphered with regard to this question. The bacterium Shewanella oneidensis , for example, has been found to convert soluble uranium, chromium and soluble nitrogen into insoluble forms. The advantage is seen in the fact that the insoluble substances can be washed out less easily and thus better ground and running water protection is provided.

biotechnology

The biotechnology is investigating how it can improve the performance of organisms used for bioremediation, using biotechnological methods.

The range of possibilities was further expanded with methods of genetic engineering . Today it is possible, for example, to implant genes from bacteria that are difficult to cultivate into other bacteria and thus use the positive properties of the newly created organisms. In order to be able to control them better, genes are implanted in them that make them dependent on the supply of certain substances, so that they die without them. Also z. B. Planted genes for phosphors for marking. The modified strains are called "genetic engineered microorganisms", mostly GEMs for short. GEMs are suitable for various areas of application such as B. contamination with oil, degradation of aromatic compounds in oxygen deficiency conditions or heavy metals have been developed. The use of GEMs is widely criticized. The main point of criticism is that released bacterial strains can no longer be controlled or retrieved and the properties of the new strains could be transferred to other strains through horizontal gene transfer. The high expectations of the technical advantages have also not been confirmed in many application examples. It has not yet been used in the field beyond field tests.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Thomas M. Smith, Robert L. Smith: Ökologie , Pearson Studium Verlag, page 850, ISBN 978-3-8273-7313-7
↑ A. Bani, Imeri, A., Echevarria, G., Pavlova, D., Reeves, RD, Morel, JL, Sulçe, S .: Nickel hyperaccumulation in the serpentine flora of Albania . In: Fresenius Environmental Bulletin, 22 (6), pp.1792-1801 . 2013.
↑ Christopher J. Rhodes: mycoremediation (bioremediation with fungi) - growing mushrooms to clean the earth. In: Chemical Speciation & Bioavailability . 26, 2015, p. 196, doi : 10.3184 / 095422914X14047407349335 .
↑ Obidimma C. Ezezika, Peter A. Singer (2010): Genetically engineered oil-eating microbes for bioremediation: Prospects and regulatory challenges . Technology in Society Volume 32, Issue 4: 331-335. doi : 10.1016 / j.techsoc.2010.10.010
↑ Meltem Urgun-Demirtas, Benjamin Stark, Krishna Pagilla (2006): Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants . Critical Reviews in Biotechnology Vol. 26, No. 3: 145-164.
↑ Jay Shankar Singh, PC Abhilash, HB Singh, Rana P. Singh, DP Singh (2011): Genetically engineered bacteria: An emerging tool for environmental remediation and future research perspectives . Gene 480 (2011) 1-9. doi : 10.1016 / j.gene.2011.03.001
↑ Ildefonso Cases & Víctor de Lorenzo (2005): Genetically modified organisms for the environment: stories of success and failure and what we have learned from them . International Microbiology 8 (3): 213-222.

[pearson-1] ↑ ^a ^b ^c ^d ^e ^f Thomas M. Smith, Robert L. Smith: Ökologie , Pearson Studium Verlag, page 850, ISBN 978-3-8273-7313-7

[2] A. Bani, Imeri, A., Echevarria, G., Pavlova, D., Reeves, RD, Morel, JL, Sulçe, S .: Nickel hyperaccumulation in the serpentine flora of Albania . In: Fresenius Environmental Bulletin, 22 (6), pp.1792-1801 . 2013.

[DOI10.3184/095422914X14047407349335-3] Christopher J. Rhodes: mycoremediation (bioremediation with fungi) - growing mushrooms to clean the earth. In: Chemical Speciation & Bioavailability . 26, 2015, p. 196, doi : 10.3184 / 095422914X14047407349335 .

[4] Obidimma C. Ezezika, Peter A. Singer (2010): Genetically engineered oil-eating microbes for bioremediation: Prospects and regulatory challenges . Technology in Society Volume 32, Issue 4: 331-335. doi : 10.1016 / j.techsoc.2010.10.010

[5] Meltem Urgun-Demirtas, Benjamin Stark, Krishna Pagilla (2006): Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants . Critical Reviews in Biotechnology Vol. 26, No. 3: 145-164.

[6] Jay Shankar Singh, PC Abhilash, HB Singh, Rana P. Singh, DP Singh (2011): Genetically engineered bacteria: An emerging tool for environmental remediation and future research perspectives . Gene 480 (2011) 1-9. doi : 10.1016 / j.gene.2011.03.001

[7] Ildefonso Cases & Víctor de Lorenzo (2005): Genetically modified organisms for the environment: stories of success and failure and what we have learned from them . International Microbiology 8 (3): 213-222.