Wax worms (Galleria Mellonella), have an interesting enzyme present in either their saliva or digestive tract. Surprisingly, this enzyme eats and digests plastic waste.
Federica Bertocchini, head researcher at the Institute of Biomedicine and Biotechnology of Cantabria in Spain and her team published a paper in Current Biology about wax worms and how they manage to digest the polyethylene bags.
However, this is a sort of ‘chance discovery.’ In order to clean one of the beehives, she bagged the worms in a plastic bag. But when she returned, to her surprise the worms had chewed the plastic and escaped.
NEED OF THE HOUR
There is a big push these days for biodegradable resources. And for non-biodegradable ones, recycling to ensure no plastic waste is taking up space on the planet for prolonged periods of times.
Non-decomposable plastic carrier bags are one of the main offenders. As more and more bags get used and thrown away, more and more piles of waste end up accumulating.
Naturally, this has led to a lot of research in manufacturing biodegradable plastic bags. Moreover, their reuse is encouraged so that less of them need to be made.
The problem with regular carrier bags is that they’re made from polyethylene. Polyethylene is a long carbon chain that is mass produced as a plastic packaging.
A specific treatment is needed to break it into smaller biodegradable parts. Currently, corrosive chemicals are used. However, this process can take several months. Due to this. large amounts of plastic bags end up in waste sites and are not being reused.
All of this suggests that newer and more efficient ways of assisting the biodegradation of polyethylene are needed.
WORMS SHOW US THE WAY
The caterpillar larva of the wax moth of the snout moth (Pyralidae) family of Lepidoptera may hold in biodegradation of plastic.
A time-lapse of worms eating polyethylene and escaping from a plastic bag. Image credit: César Hernández/Ainhoa Goñi
To examine the wax worms’ rate of eating through the polyethylene, Bertocchini used a sample size of 100 worms and measured how much plastic was removed after 12 hours.
“We have carried out many experiments to test the efficacy of these worms in biodegrading polyethylene. 100 wax worms are capable of biodegrading 92 milligrams of polyethylene in 12 hours.” says Bertocchini.
In comparison to the wax worms capacity of eating 92 mg of plastic, previous trials from bacteria only degraded 13 mg of plastic in a 24 hour timeframe. That’s fast!
Although the wax worms were noticeably eating the plastic bags, Bertocchini and her team were unsure if the worms were digesting the polyethylene or if it was just passing through their digestive tract unharmed.
WORMS EATING PLASTIC WASTE FOR FUN
Some worms were pureed and the blended worm paste was left in contact with some plastic. After 14 hours, 13% of the plastic was gone. This suggests that the enzymes inside the worm are in fact digesting and degrading the polyethylene.
The worms’ cocoons were also left in contact with the plastic and, again, this showed that the plastic degraded over time.
“We still don’t know the details of how this biodegradation occurs, but there is a possibility that an enzyme is responsible. The next step is to detect, isolate, and produce this enzyme in vitro on an industrial scale. In this way, we can begin to successfully eliminate this highly resistant material,” says Bertocchini.
By isolating the enzyme, it can be used as a catalyst in larger scale degradation of polyethylene. This would entirely negate the need for harmful acids to be used and would have a significantly smaller timeframe compared to the current methods.
“We are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation,” Bertocchini adds.
Of course, this is within the very early stages of becoming a feasible method to completely replace current methods.
With more research, however, this is a perfectly viable and extremely environmentally friendly way to reduce the 80 million tonnes of polyethylene waste that the planet produces every year.
No wonder only these despicable worms can take care of our waste.