Hungry Worms Could Help Solve Plastic Pollution

Plastics that support Modern life is inexpensive, strong and versatile, but are difficult to eliminate and have a serious impact when they are released in the environment. Polyethylene, in particular, is the most produced plastic in the world, with more than 100 million tonnes distributed per year. Since this can take decades to decompose – and along the way can harm wildlife and degrade in harmful microplastics – its elimination is an urgent problem for humanity.

In 2017, European researchers discovered a potential solution. The wax butterfly larvae, commonly known as wax to wax, have the capacity to decompose polyethylene in their bodies. Waxing verses are considered a pest since ancient times because they parasitize the hives, feeding on beeswax. However, we now know that they are also spontaneously feeding on polyethylene, which has a chemically similar structure.

“About 2,000 wax worms can break down an entire polyethylene bag as little as 24 hours, although we think that co-suppression with food stimulants such as sugars can considerably reduce the number of worms,” ​​said Dr Bryan Cassone, professor of biology at the University of Brandon in Canada, in a press release. Cassone and her team sought how these insects could be used to help fight plastic pollution. “Understanding the biological mechanisms and the consequences on the physical form associated with plastic biodegradation is essential to use wax worms for large-scale plastic correction,” he says.

In previous experiences, Cassone and his team discovered exactly how the wax worms break down polyethylene. To understand their digestive mechanism, the Cassone team nourished polyethylene to wax the verses for several days and followed the metabolic processes of insects and changes in their intestinal environment. They found that when the wax worms ate polyethylene, their excrement liquidated and contained glycol as by-product.

But when the intestinal bacteria of insects have been removed by administering antibiotics, the amount of glycol in their excrement has been considerably reduced. This revealed that the decomposition of polyethylene depends on the intestinal microbes of wax worms.

The team also isolated bacteria of the guts of wax worms and then cultivated strains that could survive polyethylene as the only source of food. Among them was a tension of Acinetobacterwhich survived for more than a year in the laboratory environment and continued to break down polyethylene. This has revealed to what extent the intestinal flora of the wax worm is robust and persistent is in its ability to decompose plastics.

However, in reality, when it comes to consuming plastic, intestinal bacteria do not work alone. When the researchers carried out a genetic analysis on insects, they found that the wax worms supplied with plastic showed an increased gene expression relating to fat metabolism, and after being nourished in plastic, wax worms duly shown signs of increased body fat. Armed with their plastic digging intestinal bacteria, larvae can decompose plastics and convert them into lipids, which they then store in their bodies.

However, a diet only in plastic has not resulted in long -term survival of wax worms. In their last experience, the team found that wax worms that continued to eat only polyethylene died in a few days and have lost a lot of weight. It has shown that it is difficult for wax worms to continually treat polyethylene waste. But researchers think that creating a food source to help their polyethylene intake would mean that wax worms are able to maintain healthy viability on a plastic diet and improve their decomposition efficiency.

For the future, the team suggests two strategies to use the capacity of the wax worm to consume plastics. One is to mass produce wax worms that are nourished with a polyethylene diet, while providing them with the nutritional support they need for long-term survival, then integrating them into the circular economy, using the insects themselves to eliminate plastic waste. The other is to rethink the degradation route of the plastic of wax worms in the laboratory, using only microorganisms and enzymes, and therefore create a means of eliminating plastic that does not need real insects.

In the insect breeding route, a by -product would be large amounts of insect biomass – larvae without counting that have been nourished in plastic. These could potentially be transformed into a very nutritious food for the aquaculture industry, because according to data from the research team, insects could be a good source of protein for commercial fish.

This story originally appeared on Cable Japan and has been translated from the Japanese.