Microorganisms from the stomach of cows can devour certain types of plastic, such as soft drinks, food packaging, and polyethylene terephthalate (PET), which is used in synthetic fibers.
Scientists have discovered these microbes in liquids drawn from the rumen, the largest compartment of ruminants. stomachRuminants include hoofed animals such as cows and sheep. These animals use microorganisms to break down the diet of coarse plants. Lumens act as incubators for these microorganisms, digesting or fermenting the food consumed by cattle and other ruminants. University of Minnesota.. Researchers believed that some of the microbes lurking in bovine lumens should be able to digest polyester, a substance whose constituent molecules are bound by so-called ester groups.
That’s because for a herbivorous diet, cows consume natural polyester produced by a plant called cutin. As a synthetic polyester, PET shares a chemical structure similar to this natural material. Cutin occupies most of the cuticle, the waxy outer layer of the cell wall of plants, and is abundant in, for example, tomato and apple skins, the corresponding author, Doris, a senior scientist at the University of Nature.・ Rivic says. Vienna’s resources and life sciences.
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“When fungi and bacteria want to infiltrate such fruits, they are producing enzyme Livic told Live Science. Specifically, a class of enzymes called kint enzymes can hydrolyze kut. That is, water molecules initiate a chemical reaction that destroys the substance. To a bit.
In the past, Ribitsch and her colleagues have isolated such enzymes from microorganisms and realized that cattle could be the cause of similar polyester-eating insects. “These animals consume a lot of plant material and break down, so it’s likely that you’ll find such microbes,” she said, living in the stomach of a cow.
And, in fact, their new study was published in the journal on Friday (July 2nd). Bioengineering and biotechnology frontier, Researchers have discovered that microorganisms from bovine lumens can degrade not only PET but also the other two. plastic — Polybutylene adipate terephthalate (PBAT) used in compostable plastic bags, and polyethylene furanoate (PEF) made from renewable plant-derived materials.
To assess how well these rumen-derived microorganisms can eat plastic, the team incubated each type of plastic in a rumen solution for 1-3 days. You can then measure the by-products released from the plastic to determine if the bug decomposed the material into components and to what extent. The rumen solution decomposed PEF most efficiently, but the team reported that it decomposed all three types of plastic.
Then the team sampled DNA To find out from the lumen solution which specific microorganism is responsible for the deterioration of the plastic. About 98% of DNA Bacteria Kingdom, the most predominant genus PseudomonasJournal reports show that some species have broken down plastics in the past Applied Microbiology and Biotechnology And that Journal of Hazardous Materials..
Bacteria of the genus Acinetobacter It has also been shown to be harvested in large quantities in liquids, as well as some species within the genus degrading synthetic polyester, according to a 2017 report. Journal of Agricultural and Food Chemistry..
In the future, Rivic and her team want to fully characterize the plastic-eating bacteria in the rumen solution and determine the specific enzymes that the bacteria use to break down the plastic. Once you have identified enzymes that may be useful for recycling, you can genetically engineer microorganisms that produce large amounts of those enzymes without collecting them directly from the cow’s stomach. In this way, the enzyme can be manufactured easily and inexpensively for industrial use, Rivic said.
In that sense, Ribitsch and her team have already patented a recycling method that in turn exposes textile materials to various enzymes. The team identified these enzymes in a previous study. The first batch of enzyme eats up the fabric fibers of the material, and the next batch of enzyme chases a particular polyester. This works because each enzyme targets a very specific chemical structure and does not break down only the substances it encounters. In this way, textiles containing multiple materials can be recycled without first separating them into components, Rivic explained.
According to new research, bovine rumen may represent another environment for discovering these kinds of useful enzymes, but such enzymes occur in many places in nature, Manitova. David Levin, a molecular biologist and biotechnologist at the University Faculty of Biosystems Engineering, said a person who was not involved in the study.
For example, the first bacteria found to be able to consume PET Ideonella sakaiensisLevin, a species involved in the fermentation of liquor, said. He said that certain marine organisms secrete cutinase, which can break down plastics, as well as various fungi that infect land plants.
So far, scientists have been able to find enzymes that eat plastics that break down biodegradable plastics such as PET, PBAT, and PEF, but now the real challenge is to make more annoying plastic products. It’s about finding an enzyme that breaks down.
For example, plastics such as polyethylene and polypropylene are primarily composed of strong bonds between carbon atoms, which limits the ability of enzymes to grab molecules and initiate hydrolysis, Ribitch said. I am. That’s why scientists have already discovered, characterized, and commercialized enzymes that break down PET, but researchers are still looking for microorganisms that can process polyethylene and polypropylene, Levin said. Levin and his lab have identified some promising candidates in this regard, but they are still thinking of ways to maximize their ability to eat bug plastic.
According to Rivic, her team is also keeping an eye on microbes that can consume polyethylene, suspecting that insects may be lurking in the cow’s stomach. “In a huge community like lumen fluid, you may find enzymes that also break down polypropylene and polyethylene,” she said.
Originally published in Live Science.
Microbes in the cow’s stomach help recycle plastic
Source link Microbes in the cow’s stomach help recycle plastic