Biodegradable plastic developed from 'tree glue'

Scientists have found that a natural 'tree glue' which stiffens plant cells can be turned into a strong, biodegradable plastic.

The natural glue called lignin holds cellulose fibres together.

Researchers from the University of Warwick in the UK genetically modified a bacteria called Rhodococcus jostii to turn lignin into useful chemicals.

There are only a small number of organisms that can break down lignin.

"Normally the bacteria uses it for growth, and breaks it down into small molecules which it uses as food to grow," said Professor Tim Bugg from Warwick.

"So we are trying to intercept that process so it still can grow but it can do something for us at the same time," Bugg was quoted as saying by 'The Telegraph'.

"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," he said.

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.

Each year more than 300 million tonnes 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.

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.