How Kyoto Institute of Technology and Keio University Ideonella sakaiensis bacterium eats polyethylene terephthalate

“When I think it through, I don't really know where it gets us. I don't see how microbes degrading plastics is any better than putting plastic bottles in a recycling bin so they can be melted down to make new ones”

Associate Scientist Marine Chemistry & Geochemistry Dr. Tracy Mincer of the Woods Hole Oceanographic Institution commenting on the discovery of Ideonella sakaiensis that eats plastic

Looks like PET (polyethylene terephthalate) the starting material used to make 50 million tons of PET plastic products annually, is biodegradable after all.

A Japanese research team from Kyoto Institute of Technology and Keio University has discovered a bacterium that eats plastic as reported in the article “Newly discovered bacteria can eat plastic bottles”, published March 11, 2016 by Deborah Netburn, Physorg. 

The exotic bacteria, known as Ideonella sakaiensis, was discovered by the researchers who had taken a 250 PET-contaminated sample that included including sediment, soil and wastewater from a plastic bottle recycling site. The researchers were looking for evidence of bacteria that could eat plastic and their researchers, published in the journal Science, confirms this.

This discovery is huge as PET is used not only in plastic bottles but also in a wide array of products:

1.      Clothing

2.      Food Trays

3.      Packaging

Albeit cheap to produce, it doesn’t biodegrade, with only a variety of mushroom called Pestalotiopsis microspora (Yale University, 2012) and fungi such as Schizophyllum commune and Pleurotus ostreatus known to eat similar plastics as reported in my blog article entitled “Katharina Unger's Fungi Mutarium Mushroom Grower - How Plastic Munching Mushrooms can be a solution to Plastics in Jamaica”. 

So how does this Ideonella sakaiensis eat plastic?

How Ideonella sakaiensis eat plastic – Great Plastic Patch and Landfill eaten by GM bacteria

Based on the research by the Japanese research team from Kyoto Institute of Technology and Keio University, it seems to use a two step process involving specially designed enzymes as noted in the article “Researchers discover a bacteria that can digest plastic bottles”, published March 17, 2016 By Kelly Hodgkins, DigitalTrends.

The bacteria they isolated from the 250 PET bottle samples lives on the PET bottles. It then secretes an enzyme that breaks down the PET into an intermediary compound which is then taken inside of the bacteria to be broken down by yet another enzyme. 

Alas, the bacteria has a flaw; it takes six (6) weeks to break down a thin film of plastic, taking it time to munch away at the plastic unto it is completely reduced to carbon and energy to grow. As far as Ideonella sakaiensis bacteria is concerned, a single plastic bottle is for it sustenance well as its offspring.

The next problem is that it only operates at one temperature, which is 30 C (86 F), which isn't a huge deal, as that's great for most industrial process. But it cannot be used directly to remove the islands of plastic out in the Atlantic and Pacific Ocean.

However, if this bacteria along with fungi, mushrooms and other dentritovores exist that can eat plastic, then the possibility exists that other organisms might be out there that eat other plastics as well, as pointed out by Associate Scientist Marine Chemistry & Geochemistry Dr. Tracy Mincer of the Woods Hole Oceanographic Institution, quote: “This process could be quite common. Now that we know what we are looking for, we may see these microbes in many areas around the world.”

So recycling and banning the importation of plastics such as styrofoam as Guyana has done as described in my blog article entitled “Why Guyana banning Styrofoam and How Jamaican Bee farmers can benefit”. 

Still, this means that not only can the 1.5 billion pounds of PET items recycled in 2010 in the US. and Canada be reduced by using a GM (Generically modified) version of this bacteria, but it can also tackle the islands of plastic out in the Atlantic and Pacific Ocean. So hope burns anew as more of these dentritovores are discovered that can decompose plastics like PET.