Hungry creams can help solve plastic contamination

Plastics that support Modern life is cheap, strong and versatile, but it is difficult to get rid of it and will have a serious impact when releasing to the environment. Polyethylene, in particular, is plastic plastic worldwide that is distributed more than 100 million tonnes annually. Because it can take decades to break down – and can damage wildlife and destroy harmful microbes along the way – it is an urgent issue for humans.

In 2017, European researchers discovered a potential solution. Wax butterfly larvae, commonly known as wax creams, are capable of decomposing polyethylene into their body. Wax worms have been considered pest since ancient times because they have parasitic bees and feed on bee wax. However, we now know that they also spontaneously feed on polyethylene, which has a similar chemical structure.

“About 2,000 wax creams can break down a polyethylene bag in at least 24 hours, although we believe that planning with nutritional stimuli such as sugars can significantly reduce the number of worms,” ​​said Dr. Brian Kason, a professor of biology at the University of Brandon in Canada. Kason and his team are investigating how these insects are in control to help fight plastic pollution. “It is important to understand biological mechanisms and the consequences of fitness associated with plastic analysis for the use of wax creams for large -scale plastic correction,” he said.

In previous experiments, Cason and his team have precisely understood how to break down polyethylene wax creams. To understand their digestion mechanism, the Casper team fed polyethylene to wax worms for several days and followed the metabolic processes of insects and changes in their intestinal environment. They found that as they eat polyethylene wax creams, their stools became liquid and made the glycol as a side product containing it.

But when insect bacteria are suppressed by antibiotics, glycol levels in their stools are greatly reduced. This showed that the decomposition of polyethylene depends on the gut microbes.

The team also separates bacteria from the intestine of wax worms and then cultivated strains that can survive as their food source in polyethylene. Among them was a strain Wisdom of the graveSurvived in the laboratory environment for more than a year and continued to break down polyethylene. This showed how strong and continuous the intestinal bowl is the ability to decompose plastic.

However, in reality, when it comes to plastic consumption, intestinal bacteria do not work alone. When the researchers did genetic analysis on insects, they found that plastic wax creams increased the expression of the fat metabolism gene, and after the plastic feed, wax creams properly show signs of increased body fat. Armed with their plastic digestive intestinal bacteria, the larvae can break down the plastics and convert them to lipids, which store them in their bodies.

However, a diet only plastic does not lead to long -term survival of wax creams. In their latest experiment, the team found that wax creams that continued to eat only polyethylene in a few days and lost a lot of weight. This shows that continuous processing of polyethylene waste is difficult for wax worms. But the researchers believe that creating a food source to help consume polyethylene means that wax creams are able to maintain a healthy survival in a plastic diet and improve their decomposition efficiency.

Looking at the future, the team suggests two strategies to use the ability to use wax in plastic use. One is that they produce wax creams that are fed in the polyethylene diet, while providing them with nutritional support for long -term survival and then integrate them into a circular economy and use insects themselves to dispose of waste plastic. Another case, redesigning the plastic destruction of wax worms in the laboratory, only by using microorganisms and enzymes, and thus creating a plastic disposal means that do not require real insects.

In the path of insect breeding, a by-product can be large amounts of insect biomass-numerous plastic-fed plastic. These can potentially become a highly nutritious feed for the aquaculture industry, as insects can be a good source of protein for commercial fish.

This story appeared first Wired Japan And translated from Japanese.