Scientists create eco-friendly plastic from tree molecules

science Editor BIODEGRADABLE plastic that can be tossed out with food scraps could be on the shelves within five years after scientists found an ingenious way to turn “tree glue” into packaging.

Researchers at the University of Warwick have found that a natural glue called lignin, which stiffens plant stems by holding cellulose fibres together, can be turned into a strong, mouldable plastic.

Lignin is a by-product of the paper making process. While it is useful in plants, it causes paper made of wood pulp to weaken and discolour quickly, and so it is removed.

In its raw form it is useless, but Prof Tim Bugg at Warwick University has developed a way to use genetically modified bacteria to turn the glue into useful chemicals.

He found that a bacteria called Rhodococcus jostii, which lives in the soil and feeds on the glue, can be genetically tweaked so that it turns lignin into high yields of biodegradable plastic.

Speaking at a briefing in London on how to deal with the world’s plastic waste problem, Prof Bugg said: “I have been working on lignin for 40 years and when I started people said ‘you’re wasting your time’ but now people are thinking this is possible. Still difficult, but it is possible.”

There are only a small number of organisms that can break down lignin and Prof Bugg’s team are using the genetic material from two strains of bacteria to speed up the process.

“Normally the bacteria uses it for growth, and breaks it down into small molecules which it uses as food to grow,” he added.

“So we are trying to intercept that process so it still can grow but it can do something for us at the same time.

“Because lignin is complex, as you break it down you get a complex mixture. But what’s nice with these bacteria is they are able to funnel all this. We are hoping in five years that we will have something.”

The Government has promised to crack down on plastic waste, which is finding its way into the oceans, where it harms wildlife, and has promised to ban single use products. Theresa May described plastic waste as “one of the greatest environmental challenges facing the world”.