Plastic waste is one of three main enemies nowadays, along with climate change and coronavirus. Even though we are still focusing on combatting the coronavirus now, but it doesn’t mean that we already forget about the other two.
This is also the reason for us to talk about plastic waste. We want to remind you that we are still fighting this very enemy. However, we are not going to spread more terror in this article, instead we are going to tell you something incredible.
While we are still finding a vaccine to fight coronavirus and still wrestling with regulations to fight climate change, we might already find the answer to plastic waste. The answer for this problem might lie in the smallest living organisms, microbes.
The bacteria are so powerful that it can ‘melt’ plastic that even fire cannot melt. Let us introduce you to these little heroes.
Polystyrene And Polyurethane
There are many kinds of plastic, and two of those are polystyrene and polyurethane plastic. Both of them are the ones we usually use in our daily lives, even though each kind of plastic serves different use from another.
Polystyrene plastic is composed of carbon and hydrogen atoms, usually eight of each atom, and forms hard plastic. The kind of hard plastic we find in our laptop is polystyrene, and it is not heat-resistant. Usually, polystyrene plastic will melt when exposed to heat about 200 to 300 degrees.
On the other hand, polyurethane is the more complex one. It is formed with 4 different atoms, which are hydrogen, oxygen, carbon, and nitrogen. Polyurethane plastic is much more flexible than its polystyrene counterpart.
Polyurethane plastic is more resistant to heat compared to polystyrene. It can withstand heat up to 700 degrees and is usually used to create fire-retardant materials. When exposed to extreme heat, it doesn’t melt like polystyrene but it would char instead.
Polyurethane plastic is also resistant to all chemicals, while polystyrene is far more reactive to chemical exposure. Both kind of plastic are the ones we usually use in our daily life, and both are hard to decompose naturally.
Since we are talking about two kinds of plastics, we will talk about each type one at a time. First, we are going to talk about the hard plastic, and what kind of bacteria can help us to eliminate polystyrene waste in the future.
The name of the bacteria is Pseudomonas aeruginosa, which can be found easily in the guts of superworms. Yes, we are talking about ‘that’ superworms we usually buy in pet shops to feed our pet reptiles, fish, and birds.
Former research has discovered that superworms are able to somehow digest polystyrene plastic materials. And after a lot of studies, it was discovered that Pseudomonas aeruginosa in superworms’ guts is the one responsible for this ability.
While inside the superworms, the bacteria can digest 70% of polystyrene provided by the researchers only in 21 days. But to make it more efficient in putting it into practical field, Jiaojie Li, Dae-Hwan Kim and colleagues from Daegu Gyeongbuk Institute of Science and Technology recently conducted a study to breed the bacteria outside of superworms’ guts.
Good news, it worked well and now researchers are trying to put this finding into real case-study. The researchers have even identified one particular enzyme from the bacteria, called serine hydrolase which is responsible for most of the work. In the future, further study may discover artificial way to produce the enzyme and melt all polystyrene waste at once.
Strong Plastic Decomposer Bacteria
Now we are talking about the ‘unbeatable’ polyurethane plastic that cannot be destroyed by heat, chemicals, and pressure. It seems impossible to break this plastic down, but a species of bacteria called Pseudomonas sp. TDA1 have proven that it is actually possible.
The kind of flexible plastic commonly used in refrigerator and footwear is a source of nitrogen and carbon for Pseudomonas sp. TDA1. The bacteria can chew that chemical bonds between the elements, and use the broken-down nitrogen and carbon atoms for their own.
“The bacteria can use these compounds as a sole source of carbon, nitrogen and energy. This finding represents an important step in being able to reuse hard-to-recycle PU (polyurethane) products,” said Hermann Heipieper, microbiologist from the Helmholtz Centre for Environmental Research-UFZ in Germany.
The discovery was literally made in a landfill where researchers accidentally found abundance of brittle PU plastic. Immediate genomic analysis was conducted to uncover the suspect, and several other experiments to work out on the bacterium’s capability followed.
According to a data, more than 3.5 million tons of polyurethane plastic is produced each year only in Europe alone. That much plastic is still not being processed nor being eliminated from our landfill, and with this finding we might finally find a way to get rid of the plastic waste.
In Search For Better Plastic
Plastic instantly became a favorite since its discovery, because it had so many features that any other compounds didn’t. However, lesser people knew that their new favorite thing was actually a nightmare in disguise for the nature.
The discovery of plastic-eating microbes is the answer for our plastic pollution problem. “Post-consumer plastics are already a major challenge for the environment and will be an even bigger one in the future,” the researchers wrote in their paper.
The thing is, those microbes that the researchers discovered the ability are not rare in our nature. They can be found and possibly can be ‘breed’ to make full use of. Many other researchers are currently searching for eco-friendlier ‘plastic’, that can be naturally decomposed faster than ordinary plastic.
But until the time comes, we are the ones responsible for our own plastic pollution. Reducing our plastic consumption is not that hard, we just need to make use of reusable containers and bags to replace single use plastic.
In this era, we are also given so many options and chances to reduce our plastic consumption. In example, many supermarkets are already banning single use plastic. well, the bright light is finally appearing at the end of the road, we just need to follow the light.