The bug that eats PLASTIC: Bacteria that breaks down bottles and bags could help clean up the planet

Japanese researchers have discovered a bug that 'eats' PET
Screened bacterial candidates able to break down the tough material
They found Ideonella sakaiensis 201-F6 which is able to tackle PET film
Discovery offers hope there may one day be a new way to clean up Earth

Millions of non-biodegradable plastic bottles containing polyethylene terephthalate, or PET are made every year - and many end up littering streets and oceans.

Now Japanese researchers have discovered a bug that 'eats' these compounds, offering the tantalising hope of a cleaner planet in years to come.

By screening bacterial candidates able to break down the tough material, they came across Ideonella sakaiensis 201-F6, which is able to use PET as its source of energy.

Japanese researchers have discovered a bug that 'eats' PET, offering the tantalising hope of a cleaner planet. Image 'E' and 'F' shows I. sakaiensis cells grown on PET film for 60 hours, while 'G' shows an image of a degraded PET film surface with an inset of intact film and 'H' shows a timeline for PET film degredation

PET is highly resistant to biodegradation and there are huge piles of bottles and fibres containing the plastic littering oceans, towns and dumps 70 years after use.

It's not broken down because there is an absence or low activity of catabolic enzymes that can attack its plastic constituents.

Polyesters containing a high ratio of components, such as PET, are chemically inert, resulting in resistance to microbial degradation.

Before now, only very few species of fungi have been found to break down PET, but researchers from Keio University in Tokyo have identified a bacterial hero.

PET is highly resistant to biodegradation and there are huge piles of bottles (stock image) and fibres containing the plastic littering oceans, towns and dumps 70 years after use

PLANKTON'S PLASTIC DIET

Plastic has been found inside the digestive tracts of turtles, sea birds and whales, but it appears plastic litter in our oceans is also clogging up the insides of the tiny plankton that many larger sea creatures feed on.

For the first time copepods – tiny creatures that feed on algae in the ocean – have been filmed eating grains of plastic while feeding.

The video shows microscopic polystyrene beads being drawn towards the creature.

The beads can then be seen accumulating in the creature's body.

Normally copepods feed on species of algae using chemical and touch receptors to discriminate what they can and can't eat.

They collected 250 samples of PET debris and screened for bacterial candidates that depend on PET film as a primary source of carbon for growth.

The team identified a novel bacterium, which they named Ideonella sakaiensis 201-F6, which could nearly completely degrade a thin film of PET after six weeks at a temperature of 30°C (86°F).

Further investigation identified an enzyme called ISF6-4831, which works with water to break down PET into an intermediate substance, which is then further broken down by a second enzyme, ISF6-0224.

These two enzymes can break down PET into its simpler building blocks.

Remarkably, these enzymes seem to be unique in their function compared to the closest related known enzymes of other bacteria, raising questions of how these plastic-eating bacteria evolved.

Shosuke Yoshida at the Department of Biosciences and Informatics, at Keio University said: 'PET is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern.

They collected 250 samples of PET debris and screened for bacterial candidates that depend on PET film as a primary source of carbon for growth. The PET structural formula is shown above

'Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy.

'By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source.

'When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid.

'Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol.'

Commenting on the discovery, which was published in the journal Science, Uwe Bornscheuer at, Greifswald University in Germany said: 'The degradation process is relatively slow - complete degradation of a small PET film took six weeks.

'Nevertheless, the discovery may have important implications for PET recycling.'

NO MORE PLASTIC IN SHOW GELS AND FACE SCRUBS

Tiny plastic beads used in face scrubs, shower gels and toothpastes are to be phased out by the cosmetics industry in an attempt to protect ocean life.

Cosmetics Europe, which represents more than 4,000 personal care product manufacturers, has issued a recommendation to remove microbeads from cosmetics.

It follows sustained campaigning by environmental groups and research showing the tiny fragments of plastic can now be found in almost every habitat on the planet.

Tiny plastic beads used in face scrubs, shower gels and toothpastes are to be phased out by the cosmetics industry in an attempt to protect ocean life. The tiny beads (pictured) are so small that they pass through the water filtration process and work their way to the sea

Cosmetics Europe said it was recommending its members 'discontinue' the use of microbeads in 'wash off cosmetic and personal care products for exfoliating and cleansing purposes' from 2020.

Instead, companies should seek alternative natural exfoliants to replace microbeads, such as ground fruit seeds.

But the a statement released by the organisation seemed to suggest company's may still be free to use some types of biodegradable plastics.

It said: 'Cosmetics Europe recommends its membership to discontinue, in wash-off cosmetic products placed on the market as of 2020, the use of synthetic, solid plastic particles used for exfoliating and cleansing that are non-biodegradable in the marine environment.'

The news was given a cautious welcome by environmental groups but many warned the deadline of 2020 is still to far away.

Recent studies have shown that fragments of plastic now make up a significant proportion of the sand on beaches around the world.

Scientists also found a new type of sedimentary rock is forming from the plastic mixing with sand and other materials on beaches.

Plastic debris has even been found in some of the deepest parts of the world's oceans.

Zooplankton has also been filmed eating tiny plastic microbeads, suggesting its impact on the food chain may be even greater than had been believed.

మాష్టారు