Clothes are often in nylon
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A genetically modified bacteria can decompose nylon chemicals and transform them into useful products, which could one day help us recycle clothes and fishing nets.
Nylons, or aliphatic polyamides, are plastics widely used due to their high sustainability and their resistance to traction, but their recycling The rate is less than 5%.
“Production represents around 10 million tonnes per year, but for the moment there is practically no recycling,” says Nick Wierckx At the Jülich Research Center in Germany. “Even incineration is difficult because you get cyanures when you burn them. The vast majority find itself in the discharge. ”
Nylon can be dissolved in a high acid solution, but the mixture of generated chemicals is not precious enough to make this commercially useful.
Now Wierckx and his colleagues have used a combination of genetic engineering and laboratory evolution to create a strain of the bacteria Pseudomonas putida This can decompose the different compounds produced once nylon has been dissolved and transform them into something useful.
The bacteria is already known to degrade oil -based materials and break down oil in spills. He is also promising to decompose plastics.
Wierckz and his colleagues have taken a tension known as the name P. Putid KT2440 and gave him genes to help him metabolize various chemicals in dissolved nylon. They then cultivated bacteria In the laboratory on these chemicals again and again until they find a tension that prospered. The researchers continued to modify it and to culture until they have bacteria that could use nylon compounds to create useful products, such as polyhydroxybutyrate – a biodegradable plastic that is not harmful to living tissue.
“THE Pseudomonas Consumes almost all of the pre -treated plastic, “explains Wierckx.” What we can measure is that around 80 to 90% is consumed, but I think it is an analytical limitation, and it actually consumes almost everything because we see nothing there. “”
But improvements are necessary before this technique can be used commercially, explains Wierckx. For example, the amount of useful product is still only about 7% of the bacterial biomass dry at the end.
The improvement that will require an additional modification of bacteria and the adjustment of the chemicals used to modify what is supplied with microorganisms, he says. “It will probably be 10, 20, 30 years until we see that happening.”
We don't have to worry that bacteria once dissolve our underwear, however, says Wierckx. “He's not going to eat all plastics in our clothes and cars. We have to preterite the plastic so that it becomes digestible. ”
It also means that we cannot yet use bacteria to clean old fishing nets in oceans. But Wierckx hopes that having this recycling process will encourage the future collection of old nets, clothing and car engines, which contain heat resistant plastics, so that they can be recycled.
