Washington: Marine bacteria have been genetically modified to break down plastic in saltwater. The artificial organism It has the ability to degrade polyethylene terephthalate (PET), a plastic used in everything from water bottles to clothing. Microplastic pollution in the seas.
„It’s exciting because we need to address plastic pollution Marine environments,” said Nathan Crook, assistant professor of chemical and biomolecular engineering at North Carolina State University and corresponding author of the paper.
„One option is to pull the plastic out of the water and put it in a landfill, but that presents its own challenges. It would be great if we could break these down. Plastic Down as reusable products. For it to work, it needs a cheap way to break down the plastic. Our work here is a big step in that direction.”
To address this challenge, the researchers worked with two types of bacteria. The first bacterium, Vibrio natrigens, thrives in saltwater and is remarkable — in part — because it reproduces so quickly. A second bacterium, Ideonella sakaiensis, is notable because it produces enzymes that break down PET and allow it to be eaten.
The researchers took DNA from I sakaiensis, which produces enzymes that break down plastic, and inserted that gene sequence into a plasmid. Plasmids are genetic sequences that can be copied into a cell independently of the cell’s own chromosome. In other words, you can inject a plasmid into a foreign cell, and that cell will activate the instructions in the plasmid’s DNA. That’s what the researchers did here.
By introducing a plasmid containing I sakaensis genes into V natrigens bacteria, the researchers were able to get V natrigens to produce the desired enzymes on the surface of their cells. The researchers later demonstrated that V natrigens was able to break down PET in a salt water environment at room temperature.
„This is scientifically exciting because it’s the first time we’ve successfully gotten V natrigens to express foreign enzymes on its cell surface,” Crook said.
„From a practical perspective, this is the first genetically engineered organism capable of breaking down PET microplastics in saltwater,” said Tianyu Li, first author of the paper and a PhD student at NC State. „This is important because it is not economically feasible to remove plastic from the ocean and wash away the high concentrations of salts before starting any process related to breaking down the plastic.”
„However, while this is an important first step, there are still three significant hurdles,” Crook said. „First, we wanted to insert DNA from I. sakaiensis directly into the genome of V natrigens, which would make the production of plastic-degrading enzymes a more stable feature of the modified organism. Second, we wanted to further modify V. natrigens so that it would eat the byproducts it produces when it breaks down PET. capable of
Finally, V natrigens must be modified to produce a desirable end product from molecular PET, a useful feedstock for the chemical industry.
„Honestly, that third challenge was the easiest of the three,” Crook said. „Breaking down PET in salt water was the most challenging part.
„We are open to talking with industry groups to learn more about which molecules would be most desirable for producing V Natriegens,” Kruk says. „Given the range of molecules we can induce bacteria to produce, and the wide range of production, which molecules can provide an industrial market?”
„It’s exciting because we need to address plastic pollution Marine environments,” said Nathan Crook, assistant professor of chemical and biomolecular engineering at North Carolina State University and corresponding author of the paper.
„One option is to pull the plastic out of the water and put it in a landfill, but that presents its own challenges. It would be great if we could break these down. Plastic Down as reusable products. For it to work, it needs a cheap way to break down the plastic. Our work here is a big step in that direction.”
To address this challenge, the researchers worked with two types of bacteria. The first bacterium, Vibrio natrigens, thrives in saltwater and is remarkable — in part — because it reproduces so quickly. A second bacterium, Ideonella sakaiensis, is notable because it produces enzymes that break down PET and allow it to be eaten.
The researchers took DNA from I sakaiensis, which produces enzymes that break down plastic, and inserted that gene sequence into a plasmid. Plasmids are genetic sequences that can be copied into a cell independently of the cell’s own chromosome. In other words, you can inject a plasmid into a foreign cell, and that cell will activate the instructions in the plasmid’s DNA. That’s what the researchers did here.
By introducing a plasmid containing I sakaensis genes into V natrigens bacteria, the researchers were able to get V natrigens to produce the desired enzymes on the surface of their cells. The researchers later demonstrated that V natrigens was able to break down PET in a salt water environment at room temperature.
„This is scientifically exciting because it’s the first time we’ve successfully gotten V natrigens to express foreign enzymes on its cell surface,” Crook said.
„From a practical perspective, this is the first genetically engineered organism capable of breaking down PET microplastics in saltwater,” said Tianyu Li, first author of the paper and a PhD student at NC State. „This is important because it is not economically feasible to remove plastic from the ocean and wash away the high concentrations of salts before starting any process related to breaking down the plastic.”
„However, while this is an important first step, there are still three significant hurdles,” Crook said. „First, we wanted to insert DNA from I. sakaiensis directly into the genome of V natrigens, which would make the production of plastic-degrading enzymes a more stable feature of the modified organism. Second, we wanted to further modify V. natrigens so that it would eat the byproducts it produces when it breaks down PET. capable of
Finally, V natrigens must be modified to produce a desirable end product from molecular PET, a useful feedstock for the chemical industry.
„Honestly, that third challenge was the easiest of the three,” Crook said. „Breaking down PET in salt water was the most challenging part.
„We are open to talking with industry groups to learn more about which molecules would be most desirable for producing V Natriegens,” Kruk says. „Given the range of molecules we can induce bacteria to produce, and the wide range of production, which molecules can provide an industrial market?”