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BIODEGRADABLE PLASTIC MADE FROM 'TREE GLUE' COULD BE ON SHELVES WITHIN FIVE YEARS

05.07.2018
Lignin holds cellulose fibres together, stiffening plant stems, but can be turned into a strong, moldable plastic
Credit: JULIAN SIMMONDS 

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 holds cellulose fibres together, stiffening plant stems, can be turned into a strong, moldable plastic.

Lignin is a byproduct 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 Professor 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 bacterial 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 Central 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 is with these bacteria 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 the scourge of plastic which is increasingly finding its way into the oceans where it harms wildlife, and has promised to ban single use products.

Plastic is notoriously difficult to recycle - and only 12 per cent of household waste is reprocessed. The rest is either burnt or goes to landfill.

In April, Theresa May announced £60 million worth of funding to look at new ways to tackle the problem.

The Prime Minister has described plastic waste as ‘one of the greatest environmental challenges facing the world.’

Each year more than 300 million tons of plastic are produced globally, and 10 per cent will end up in the sea.

It is estimated that there is now a 1:2 ratio of plastic to plankton and, left unchecked, plastic will outweigh fish by 2050.




source:  telegraph.co.uk