PLASTIC EATING BACTERIA

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Ideonella sakaiensis is Gram-negative, aerobic, and rod-shaped is a bacterium from the genus Ideonella and family Comamonadaceae, capable of breaking down and consuming the plastic polyethylene terephthalate (PET) as a sole carbon and energy source.

DISCOVERY

In 2016, Japanese team, led by Dr. Kohei Oda from the Kyoto Institute of Technology and Dr. Kenji Miyamoto from Keio University, 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 bacterium was isolated from a consortium of microorganisms in the sediment sample, including protozoa and yeast-like cells. The entire microbial community was shown to mineralize 75% of the degraded PET into carbon dioxide once it had been initially degraded and assimilated by ‘Ideonella sakaiensis’

They identified Ideonella sakaiensis 201-F6, which could nearly completely degrade a thin film of PET after six weeks at a temperature of 86 degrees Fahrenheit (30 degrees Celsius). The PET degrading enzyme of Ideonella sakaiensis, has been genetically modified and combined with MHETase to break down PET faster, and also degrades PEF. This may possibly, along with other approaches, be useful in efforts for recycling and upcycling of mixed plastics.

HOW DOES IT WORKS?

Plastics are polymers, meaning they have a long repeating chain of molecules.

These long chains are exceptionally durable, making them tough to break down and decompose naturally.

If these long polymer chains could somehow be broken down into shorter chains, then they could be recycled easier to form new plastics.

This is exactly what the newly discovered bacteria do; break down the molecules of the plastics into their original building blocks.

By secreting an enzyme which “eats” the chemical bonds in the chain, the molecules are broken down into their smaller components, making them easier to be recycled.