Dehalococcoides
| Dehalococcoides | ||||||||||
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| Systematics | ||||||||||
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| Scientific name of the class | ||||||||||
| Dehalococcoidia | ||||||||||
| Löffler et al. 2013 | ||||||||||
| Scientific name of the family | ||||||||||
| Dehalococcoidaceae | ||||||||||
| Löffler et al. 2013 | ||||||||||
| Scientific name of the genus | ||||||||||
| Dehalococcoides | ||||||||||
| Löffler et al. 2013 |
The genus Dehalococcoides is the only group of bacteria that are capable of the reductive dehalogenation of chlorobenzenes , polychlorinated dioxins , polychlorinated biphenyls and chlorinated ethenes . Some strains are isolated (e.g. 195, CBDB1, FL2, BAV1, VC, GT, DCMB5). CBDB1 strain was isolated from the anoxic sediment of the Saale . All Dehalococcoides were brought together under the common name Dehalococcoides mccartyi . While most of the D. mccartyi are known for their activity against toxic chlorinated hydrocarbons such as perchlorethylene or trichlorethylene, which can be converted into harmless ethene, strain CBDB1 is primarily known for the conversion of halogenated aromatics such as chlorinated phenols, benzenes, biphenyls (PCBs ) and dioxins (PCDDs).
Genome research
The genomes of some strains have been sequenced and published. The sequences are among the smallest genomes of free-living bacteria known to date. From the sequences it can be deduced that both representatives are highly specialized in reductive dechlorination as an energy source. 32 complete operons homologous to reductive dehalogenases were found in strain CBDB1, and 18 of these genes in strain 195. In contrast, there are no genes in the genome for nitrate, sulfate or fumarate reduction, and genes that could code for cell wall synthesis are also missing.
biochemistry
A more precise knowledge of the biochemical activities of the enzymes encoded by Dehalococcoides would allow the dehalogenation potential of Dehalococcoides populations in contaminated areas of the environment to be precisely predicted and used biotechnologically.
literature
- L. Adrian, U. Szewzyk, J. Wecke, H. Görisch: Bacterial dehalorespiration with chlorinated benzenes. In: Nature 408, 2000, pp. 580-583.
- M. Kube, A. Beck, SH Zinder, H. Kuhl, R. Reinhardt, L. Adrian: Genome sequence of the chlorinated compound-respiring bacterium Dehalococcoides species strain CBDB1. In: Nat Biotechnol . 23, 2005, pp. 1269-1273.
- X. Maymó Gatell, YT Chien, JM Gossett, SH Zinder: Isolation of a bacterium that reductively dechlorinates tetrachloroethene to ethene. In: Science 276, 1997, pp. 1568, 1571.
- R. Seshadri et al .: Genome sequence of the PCE-dechlorinating bacterium Dehalococcoides ethenogenes. In: Science. 307, 2005, pp. 105-108.
Individual evidence
- ↑ Frank E. Löffler, Jun Yan, Kirsti M. Ritalahti, Lorenz Adrian, Elizabeth A. Edwards: Dehalococcoides mccartyi gen. Nov., Sp. nov., obligately organohalide-respiring anaerobic bacteria relevant to halogen cycling and bioremediation, belong to a novel bacterial class, Dehalococcoidia classis nov., order Dehalococcoidales ord. nov. and family Dehalococcoidaceae fam. nov., within the phylum Chloroflexi . In: International Journal of Systematic and Evolutionary Microbiology . tape 63 , no. 2 , 2013, p. 625-635 , doi : 10.1099 / ijs.0.034926-0 ( microbiologyresearch.org [accessed September 18, 2017]).
- ↑ Dehalococcoides ethenogenes. on: microbewiki.kenyon.edu