Researchers Look to Mealworms To Help Solve Africa’s Plastic Waste Problem

As Africa, alongside the rest of the world, contends with a growing challenge of plastic waste, scientists from the International Centre of Insect Physiology and Ecology (icipe), have found a promising solution to the menace – in the mealworm.
 
In a paper published in Scientific Reports journal, the researchers report the potential of the lesser mealworm (the larvae of a darkling beetle species, known scientifically as Alphitobius), to consume plastic. The scientists have also noted a consortium of important bacteria in the gut of the mealworm, which help in the digestion of plastic. Thus, either the mealworm or the bacteria could be harnessed to biodegrade plastic.
 
“Although often mistaken for ordinary worms, mealworms are the larvae of the darkling beetles. Worldwide, yellow mealworms, the larvae of a darkling beetle species called Tenebrio molitor, have been used to biodegrade plastic. However, this is the first time that the lesser mealworms, which are native to Africa, have been documented to have this capacity,” explains Dr Fathiya Khamis, icipe Senior Scientist, and lead researcher of the study.

Globally, more than 400 million tonnes of plastic are produced annually; less than 10% is recycled and an estimated 19 – 23 million tonnes end up in lakes, rivers and seas. Plastics may contain toxic chemicals, and the waste contaminates water, affects quality of soils, ecosystems and essential services, creates breeding grounds for mosquitoes, and ends up in the food chain. While Africa produces only 5% and consumes 4% of global plastic, there is increased use of single-use plastic. The continent is now the world’s second most polluted.

The icipe researchers tested the ability of the lesser mealworm to consume polystyrene, one of the major microplastics that is fast accumulating both in land and water bodies. Polystyrene waste comes from the commercial application of its most common form, styrofoam. This material is used in food storage containers, packaging of equipment, disposable plates and cups, and insulation in construction. Various methods, including chemical, thermal and mechanical, are used to recycle polystyrene. However, these approaches are expensive and they also produce toxic compounds that are harmful to human, environment and biodiversity.