NAIROBI, Kenya- Could the answer to our plastic waste crisis be wriggling around in poultry houses? Recent discoveries suggest yes.
Researchers at the International Centre of Insect Physiology and Ecology (ICIPE) have found that lesser mealworm larvae, native to Africa, are capable of breaking down polystyrene – a common but notoriously tough plastic.
These “plastic-eating” bugs could help revolutionize waste management by giving us access to naturally occurring enzymes that break down one of the world’s most persistent pollutants.
Plastic pollution is a growing global concern, with polystyrene, better known as Styrofoam, presenting a significant challenge.
This material is used for everything from packaging food to insulating electronics and is virtually indestructible under traditional recycling methods.
Chemical and thermal recycling processes are costly and often produce harmful pollutants, pushing researchers to explore biological alternatives.
Enter the Kenyan lesser mealworm, the larval stage of the Alphitobius darkling beetle, which typically thrives in poultry farms.
These resilient larvae can survive on polystyrene thanks to bacteria in their guts that break down the plastic into manageable components.
While similar species have been found to consume plastics, this is the first time an insect native to Africa has been documented with this capability.
The discovery could hold significant implications for regions like Africa, which faces unique plastic pollution challenges due to high importation and limited recycling infrastructure.
Researchers carried out a month-long study to test the mealworms’ plastic-busting abilities. They divided the larvae into three diet groups: polystyrene-only, nutrient-dense bran, and a mix of polystyrene and bran.
The findings were clear: while the polystyrene-only diet supported the mealworms’ survival, those fed a mix of bran and polystyrene consumed plastic more effectively.
The insects on the mixed diet broke down approximately 11.7pc of the polystyrene over the study period, showing that they need a balanced diet for optimal plastic degradation.
A deeper look into the mealworms’ gut bacteria highlighted the key role these microbes play.
Insects fed polystyrene showed increased levels of Proteobacteria and Firmicutes – bacterial groups known to digest complex materials.
Strains like Kluyvera, Lactococcus, and Klebsiella flourished in the polystyrene-fed larvae, suggesting these microbes may be responsible for producing plastic-degrading enzymes.
These enzymes break down plastic polymers into simpler molecules, which the larvae then use as an energy source.
By isolating these bacteria and their enzymes, researchers hope to create a “microbial toolkit” that can tackle plastic waste without needing to release live insects into the environment.
This approach could allow plastic waste processing at an industrial scale, applying the enzymes directly in landfills, factories, or recycling facilities.
The Kenyan lesser mealworm’s plastic-digesting potential has researchers excited for the future. While other insect species, like the yellow mealworm, have demonstrated similar abilities, this regional focus on African insects may reveal new insights into handling plastic waste in warmer climates.
Africa’s unique environmental conditions, along with the mealworm’s adaptability, could prove advantageous in scaling up these microbial solutions for broader waste management applications.
The next steps include isolating the specific bacterial strains involved in plastic degradation and understanding how to cultivate these enzymes at scale. Researchers are also exploring the possibility of using the leftover insect biomass in animal feed, provided it is safe and nutritious.
