Researchers have recently created a genetically modified bacteria which is capable of transforming plastic pollutants into pain drugs. This innovation, spotted by ScienceNewscould help the industry manage a source of problematic pollution and even value it.
Plastics are tremendously useful materials in many areas of our society. But many of them also pose a big problem at the environmental level, especially because of their resistance to degradation. They are indeed made up of long polymers channels which do not exist in their natural state, and microorganisms therefore did not have time to acquire the weapons necessary to decompose them.
Many researchers therefore explore different ways of getting rid of, and even recycling this major source of pollution. Most of these approaches are based on genetic engineering; By modifying the internal machinery of certain bacteria, specialists have already managed to make them capable of breaking these polymer chains, sometimes even to transform them into useful compounds.
Genetic engineering at the rescue
An interesting example recently emerged from the University of Edinburgh, Scotland. The team at the origin of this work began their research with They exhibited chillor E. colian extremely common bacteria found in particular in the digestive system many animals – including humans. It is also one of the main model organizations used in biology; It was so studied that almost all the elements of its genome and its metabolism are already known from start to finish, which considerably facilitates their genetic manipulation.
The study authors began by testing their approach with a molecule called Para-Aminobenzoic acid, or Paba. It is a very important compound in the metabolism of bacteria, because it is a precursor that allows them to produce folic acid. The latter is essential to life, because it participates in the production of DNA, RNA and amino acids. Without him, cells cannot be replicated properly, preventing organisms from growing and proliferating.
The team started by deactivating the metabolic path that allows E. coli to synthesize this paba. This means that bacteria were condemned, unless they find another way of producing this acid.
In parallel, they also equipped them with a new gene associated with the production of a particular enzyme, capable of catalyzing a chemical reaction called rearrangement of Lossen. In this context, this reaction makes it possible to alter the molecular structure of a plastic to produce paba.
The researchers then provided precursors derived from PET plastic to bacteria to check if their genetic modifications had worked. Ideally, they should be able to survive by converting these precursors into paba thanks to this new metabolic pathway added artificially. Otherwise, they would have been deprived of their ability to produce folic acid essential for their survival, and would have dusted quickly.
At the end of the process, the researchers found that E. coli continued to proliferate. Proof that the rearrangement of Lossen took place properly, and that the team could go to the next stage.
From plastic to paracetamol
From there, they made a new series of genetic modifications to add a new additional metabolic route, this time to allow E. coli To convert the paba into acetaminophen – a compound better known as paracetamol, the active ingredient of many mainstream painkillers. After this new modification, E. coli was capable of converting 92 % of pioneers based on plastic into paracetamol within 48 hours!
It is a very encouraging result. Indeed, the production of paracetamol is largely based on phenols, derivatives of benzene which is itself obtained from crude oil. In other words, the production of this very common painkillers depends on the petrochemical industry. This means that in theory, the approach demonstrated by the authors of the study could make it possible to make a stone two shotsby recycling problematic pollutants to produce paracetamol without using more fossil materials.
A promising concept, but still far from mature
However, it should be noted that this study only presents proof of concept. As it stands, it will not be Not easy to integrate it into a large -scale industrial process.
This concerns in particular the method used by the authors of the study to produce these famous precursors derived from PET plastic. They used a process of depolymerizationwhich makes it possible to break the polymers channels which constitute the material. However, it is a delicate reaction which can also form other unwanted by-products if it is not very rigorously controlled. Managing large amounts of recycled PET plastic, and therefore often contaminated by other chemical species, will therefore be complicated.
According to Dylan Domaille, a chemist not involved in the study cited by ScienceNewsit will be difficult to carry out this large -scale process to produce mass paracetamol. Because even if it is technically feasible, profitability may be much lower than that of conventional production methods, based on oil.
But the idea is nevertheless promising. In the future, other genetic changes could allow E. coli to make the whole transformation chain from the start – including the conversion of raw plastic into paba precursors. If necessary, it would be enough for example to provide old bottles with altered bacteria to obtain paracetamol at the end of the chain. It will therefore be necessary to follow the evolution of this promising field of research which, in the long term, could allow us to produce lots of useful compounds using genetically modified bacteria.
🟣 To not miss any news on the Geek newspaper, subscribe to Google News and on our WhatsApp. And if you love us, we have a newsletter every morning.
