By Jackson Okata | amboleokata@gmail.com
Scientists from the International Centre of Insect Physiology and Ecology (icipe) have fronted mealworms as a promising solution to the plastic waste challenge in Africa.
In a paper published in Scientific Reports journal, the researchers say the lesser mealworm (the larvae of a darkling beetle species, known scientifically as Alphitobius), has the potential to consume plastic.
According to the scientists, there is 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.
Dr Fathiya Khamis, a Senior Scientist at icipe and lead researcher in the study, says although often mistaken for ordinary worms, mealworms are the larvae of the darkling beetles. She says the yellow mealworms, 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,” she explains.
Globally, more than 400 million tonnes of plastic are produced annually. Less than 10 per cent of this is recycled and an estimated 19 million to 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 per cent and consumes 4 per cent of the plastic produced globally, there is increased use of single-use plastic. The continent is now the 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 on land and in water bodies. Polystyrene waste comes from the commercial application of its most common form, styrofoam. The 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 also produce toxic compounds that are harmful to humans, environment and biodiversity.
“Our study showed that the mealworm can ingest close to 50 per cent of the styrofoam. We aim to conduct further studies to understand the process through which the mealworm consume polystyrene, and whether they gain any nutritional benefits from the material,” said Evalyne Ndotono, an icipe PhD scholar.
She added: “We will also explore the mechanisms of the bacteria in the lesser mealworm in the degradation of plastic. We want to understand if the bacteria are inherent in the mealworm, or if they are a defence strategy acquired after feeding on plastic.”
Additionally, the scientists will explore the ability of the lesser mealworm to degrade diverse types of plastics and to convert it into useful, safe products.
Dr Abdou Tenkouano, the icipe Director General, said the research boosts the institution’s growing body of innovations for a circular economy.
“We can exploit this knowledge to solve the plastic waste pollution, while also harnessing the benefits of mealworm, which are part of the population of highly nutritious edible insects,” he said.
The icipe study also increases knowledge on bioremediation – the use of microbes to clean up contaminated ecosystems, soil and groundwater applications. icipe says it will explore collaborative research and innovation efforts with other scientists, policymakers and industry partners, to harness the full potential of lesser mealworm and other similar organisms.
