Ideonella sakaiensis
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Ideonella sakaiensis |
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| Scientific name | ||||||||||||
| Ideonella sakaiensis | ||||||||||||
| Yoshida et al. 2016 |
Ideonella sakaiensis is a bacterium from the order Burkholderiales , whereby the genus Ideonella is not assigned to any family according to the current system (as of 2019). Ideonella sakaiensis is able tocompletely metabolizethe plastic polyethylene terephthalate ( abbreviation PET ).
features
These are gram-negative , strictly aerobic bacteria, which means that they need oxygen to grow. Ideonella sakaiensis is catalase- positive and oxidase- positive. Endospores are not formed, the cells are rod-shaped and capable of active movement ( motile ) through polar flagellation . The temperatures suitable for cultivation are in the range of 15–42 ° C (optimally 30–37 ° C), so the bacterium is a mesophilic organism. During growth, slightly acidic pH values up to pH 5.5 or slightly alkaline pH values up to pH 9.0 are tolerated, optimally it grows at pH 7.0–7.5.
metabolism
In order to meet its energy requirements, the bacterium breaks down the plastic in the first step using the enzyme PETase to form mono (2-hydroxyethyl) terephthalic acid and in the second step using the enzyme MHETase into the monomers of the plastic, ethylene glycol and terephthalic acid . These can be used by the bacteria to generate energy. Metabolic end products are water and carbon dioxide.
The bacterium was discovered by researchers led by Shosuke Yoshida of Kyoto Technical University in 2016. The researchers collected 250 half-rotten PET bottles from the waste from a PET recycling plant in the Japanese port city of Sakai and examined them specifically for microorganisms that could use the plastic as a source of nutrients.
Since PET as a potential source of nutrients was only produced in larger quantities from around the 1950s, it is obvious that the bacterial species only acquired the ability to metabolize PET within the last few decades. It is believed that the enzyme evolved from polyester-cleaving enzymes that occur, for example, in plant-digesting microorganisms.
literature
- Shosuke Yoshida, Kazumi Hiraga, Toshihiko Takehana, Ikuo Taniguchi, Hironao Yamaji, Yasuhito Maeda, Kiyotsuna Toyohara, Kenji Miyamoto, Yoshiharu Kimura, Kohei Oda: A bacterium that degrades and assimilates poly (ethylene terephthalate) . In: Science . tape 351 , no. 6278 , March 11, 2016, p. 1196–1199 , doi : 10.1126 / science.aad6359 .
Web links
Individual evidence
- ^ Jean Euzéby, Aidan C. Parte: Genus Ideonella. In: List of Prokaryotic names with Standing in Nomenclature, Systematics of Bacteria (LPSN) . Retrieved December 16, 2019 .
- ^ Jean Euzéby, Aidan C. Parte: Classification of domains and phyla - Hierarchical classification of prokaryotes (bacteria). In: List of Prokaryotic names with Standing in Nomenclature, Systematics of Bacteria (LPSN) . Retrieved December 16, 2019 .
- ↑ Somboon Tanasupawat, Toshihiko Takehana, Shosuke Yoshida, Kazumi Hiraga, Kohei Oda: Ideonella sakaiensis sp. nov., isolated from a microbial consortium that degrades poly (ethylene terephthalate). In: International Journal of Systematic and Evolutionary Microbiology . 66, 2016, pp. 2813-2818, doi : 10.1099 / ijsem.0.001058 .
- ↑ Microorganisms are supposed to destroy plastic - Heise online, accessed on August 17, 2016
- ^ Mary Halton: Recycling hope for plastic-hungry enzyme. BBC News, April 16, 2018, accessed April 16, 2018 .