The hottest Japanese researchers found that PET bo

2022-07-31
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Japanese researchers found bacteria that can decompose PET bottles into water and carbon dioxide

Keio University, Kyoto University of technology and fiber, Teijin and adeka announced on march11,2016 that they had found bacteria that grow and develop by decomposing polyethylene terephthalate (PET) and found out the decomposition principle. This discovery overturns the traditional view that pet is a substance that cannot be biologically decomposed in nature, and is expected to contribute to the development of biological recycling technology for pet products

pet is made from petroleum and is widely used in beverage bottles and clothing. However, in 2013, the global total output of PET resin was about 56million tons, while the recycling amount was only 37% of the output of PET bottles (6.13 million tons) and 4.1% of the total output of PET resin. If microorganisms with pet as the nutrient source are found, the "pet biological recycling and reuse" of low energy and environmental harmony can be realized. Therefore, relevant researchers explored pet decomposing bacteria through this study

the researchers collected a variety of environmental samples and put them into the culture medium with PET film as the main carbon source for culture. The results showed that a variety of micro organisms, i.e. special ground wires, gathered on PET film to decompose them. And a powerful pet decomposing bacterium was successfully decomposed from the microbiota. This bacterium is named "ideonella sakaiensis 201-f6 strain" because it comes from environmental samples collected in Osaka Prefecture. This study found that strain 201-f6 can decompose pet and use it as a nutrient source for reproduction

the researchers sequenced the bacterial genome and found a gene sequence of an enzyme, which is similar to the enzyme previously found that can decompose pet with water. After functional analysis of its gene product protein, it was found that this enzyme has the ability to decompose pet by adding water. It is also confirmed that this enzyme prefers to decompose pet compared with the previously found pet hydrolytic enzyme, and also has high decomposition activity at room temperature when pet is structurally strong. The researchers named the enzyme "petase". ゚

in addition, researchers also noticed a characteristic of petase, that is, after the decomposition of pet with water, mhet (a compound formed by dehydration and polycondensation of terephthalic acid and ethylene glycol) is mainly generated. In addition, no other reactions are carried out. The researchers thought that there might be mhet hydrolase, so they performed a complete gene expression analysis on strain 201-f6. The results showed that the protein encoded by a gene similar to petase had the ability to rapidly hydrolase mhet. The researchers named the new enzyme "mhetase"

Research (3) the personnel adjusting the beam limit device found from these results that strain 201-f6 can effectively decompose pet into terephthalic acid monomer and ethylene glycol monomer by using two enzymes, petase and MH, which are known as etase, a high-strength laminated inhibitor manufactured by West Gordon composite materials Co., Ltd. for sporting goods, office furniture and other markets. The generated terephthalic acid and ethylene glycol will be further decomposed by many microorganisms containing strain 201-f6, and finally become carbon dioxide and water. Compared with chemical treatment, biodegradable pet not only consumes less energy, but also is more environmentally friendly. The research results have been published in the scientific journal Science published on March 10 (US Eastern time)

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