In the US, over 2.5 billion plastic foam cups are discarded every year, most of which will take anywhere between 50 to 80 years to decompose. Considering that Americans dispose of nearly 33 million tons of plastic each year, and only 10-percent of this is actually recycled, the environmental implications of this type of pollution is truly terrifying. In addition to land and water contamination, the accumulation of plastic often leads to animal poisoning and even entanglement of fish, turtles and sea birds in the debris.
A new study, conducted by an international team of scientists, shows that the tiny mealworm could help us tackle today’s growing plastic problem. Technically the larval form of darkling beetle, these creeping organisms can safely consume Styrofoam and certain types of polystyrene. It is, in fact, the microorganisms present in the worms’ guts that are capable of biodegrading plastic, says the research recently published in the Environmental Science and Technology journal. The team said:
Our findings have opened a new door to solve the global plastic pollution problem.There’s a possibility of really important research coming out of bizarre places. Sometimes, science surprises us. This is a shock.
Led by Craig Criddle, a civil and environmental engineering professor, the research is the result of a collaboration between Stanford University and Chinese scientists mainly from Beijing-based BeiHang University. To test their theory, the team allowed 100 mealworms to feast on 34 to 39 milligrams of Styrofoam – nearly the weight of a tiny pill – every day. Thanks to a complex process of bacterial decomposition, they were able to convert more than half of the ingested plastic into carbon dioxide, much like they normally do with any kind of food.
In the next 24 hours, the animals excreted the remaining consumed Styrofoam, in the form of biodegraded fecal matter that actually looks like tinier versions of rabbit droppings. According to the researchers, the worms, living on a Styrofoam diet, were found to be as healthy as the ones eating normal food. What is more, their waste seemed safe enough to be used as animal manure, for better crop yield. An earlier research, conducted by the same group, revealed that waxworms, the larval form of Indian mealmoths, contain similar gut microbes that can decompose polyethylene, a type of plastic commonly used for making trash bags.
At present, the scientists are working to see if mealworms, and other insects, can decompose different types of plastics, including polypropylene (used in fabrics and automotive components) and microbeads (basically, minuscule polyethylene spheres that are used as exfoliants in cosmetic products). They will also check if employing this approach, of using animals to biodegrade plastic, could potentially disrupt the food chain. Another major focus, of the team, involves looking for similar solutions to tackle marine pollution. For instance, every day in Los Angeles alone, over 10 metric tons of plastic waste is dumped into the Pacific Ocean.
The project follows a 2004 research, by Stanford Woods Institute for the Environment, that aimed at evaluating the feasibility of commercial manufacturing of eco-friendly building materials and nontoxic bioplastics. The significance, of the current breakthrough, lies in the fact that it offers a solution to the world’s rapidly-mounting Styrofoam waste, which until now was believed to be completely non-biodegradable. Additionally, it provides greater insight into the process of microbial decomposition that the mealworms employ to biodegrade plastic debris. Replicating the mechanism could potentially lead to the development of safer and more efficient management of plastic pollution.
Source: Stanford University