There is always such an experience in life. I bought a lot of goods in the store and found that I forgot to bring my environmental protection bag after checkin
There is always such an experience in life. I bought a lot of goods in the store and found that I forgot to bring my environmental protection bag after checking out. At this time, the copper plastic bag is a good choice, which can easily take the goods home. According to statistics, as many as 500 million disposable plastic bags are used all over the world every year.
Do you know that plastic bags were invented for reuse? Swedish engineer Stern submachine gun Gustav Turing invented the first plastic bag. Because compared with paper bags, plastic bags are not easy to be damaged by moisture or pulling, which is beneficial to reuse and can reduce tree felling, and compared with paper bags, plastic bags can also carry heavy objects. Through the invention of plastic bags, Turing hopes to solve the environmental problems caused by paper bags. However, up to now, more than half of plastic bags have not achieved the original intention of "reuse", and many plastic bags have been thrown into nature at will, causing another ecological pressure.
In the past few years, plastic products have seriously affected the environment and ecology. A few years ago, we used to stick a straw into the turtle's nose. Just over 8 minutes of Youtube video awakened many people's awareness of environmental protection and began to refuse to use disposable plastic straws. The Environmental Protection Department of the Executive Yuan also announced the use standard of disposable plastic straws in May 2008. In addition to restricting the disposable use of plastic straws, some shops and institutions have also introduced discounts on their own environmentally friendly tableware. For disposable plastic products that have to be used, * * * also advocates recycling.
In 2065438+2008, the total amount of plastics recovered in Taiwan Province Province of China was 530,000 metric tons, of which the recycling amount of Baote bottles was as high as 5.4 billion, the resource recycling rate was the third in the world, and the recycling amount of Baote bottles was as high as 95%. Even so, 200-300 million Bote bottles still flow into nature every year. Therefore, in addition to plastic reduction, scientists began to think about how to shorten the decomposition cycle of rubber products.
It is found that there are so many bacterial plastic products that can eat plastic, let's start with the most common pet in people's livelihood (ethyl phthalate).
PET is a common plastic material, which is found in clothes, packaging and carpets, among which the most famous product of PET is Baote bottle. PET has become a common plastic material because of its low price and portability. However, because the ester bond of the two monomers polymerized in the structure is not easy to decompose, it has amazing biodegradability. It takes at least 450 years to decompose a Potter bottle.
Even though the data shows that the recovery rate of Bote bottles is not low at present, there are still 200-300 million Bote bottles that are not successfully recovered every year in Taiwan Province Province, China. These forgotten bottles were eventually abandoned in the human life track, better thrown into landfills, and unfortunately brought into mountains or oceans, causing harm to wildlife again.
PET has amazing biodegradability, and it takes at least 450 years to decompose a Bot bottle. Pexels, wait. As I said just now, it takes 450 years to decompose bottles, so there is still a way to decompose them, so just find out who has been decomposing bottles these years, and things will be fine, Joe.
That's right! The first thing that came to mind was the research team from Japan, who brought all the sediments, wet soil and wastewater from the Baote bottle recycling field back to the laboratory, as long as there were environmental samples that came into contact with the decomposed Baote bottle wreckage. The research team cultured these samples on PET plastic film, hoping to see whether there are microorganisms that decompose PET, which can generate energy by decomposing PET and maintain metabolism and synthesis reactions in cells.
There really is.
20 16, a Japanese research team discovered a new type of bacteria, which loves to "eat" plastic. This bacterium can completely decompose the PET film in about 6 weeks. The research team named it "Ideonella sakaiensis".
Enzyme, the catalyst of biological production, discovered new bacteria, and then what? The quickest way to know what magical powers he has is to send them to sequencing.
According to the sequencing results, the researchers found that bacteria carry a hydrolase, which may be related to Sakamoto Osaka's ability to decompose PET. To prove this conjecture, the researchers purified the enzyme and tested its ability to decompose PET. It was found that the enzyme had the best reaction efficiency in decomposing PET at 30℃, so it was named PETase.
After finding out the key mechanism of PET decomposition in Sakamoto Osaka, the team successfully purified PETase by chemical method, and got rid of many conditions in microbial experiments. However, being able to decompose the PET plastic film within 6 weeks can only prove that the enzyme has the ability to decompose, but it is far from enough to face 200-300 million PET bottles thicker than the film, so scientists began to think about how to speed up the reaction of decomposing PET.
Find the enzyme that can decompose plastics, can you hurry up? 20 18 the research team of Portsmouth university in England analyzed the structure of PETASE according to the previous research, and found that the amino acid sequence of PETase was 52% similar to the hydrolase TfH of thermophilic actinomycete fusca. However, the substrate specificity between them is different. The structure of PETase is similar to α/β hydrolase which catalyzes the decomposition of keratin and fatty acids. Therefore, the research team hopes to design an enzyme that can decompose PET faster by changing the structure of PETase.