Plastic Devourer: A Unique Insect of Its Kind Discovered in Africa

© Krizjohn Rosales/Pexels

If the entire planet is drowning in plastic pollution, the African continent is facing even more critical levels of pollution. That's why the discovery of this tiny larva of the small Kenyan mealworm, a beetle belonging to the genus Alphitobius, could be a game changer. Indeed, this species has the remarkable ability to break down polystyrene, the plastic that is omnipresent in our food, electronic and industrial packaging.

This discovery is all the more significant since it is the first native species in Africa to exhibit this ability. Their work was published in the journal Scientific Report on September 12.

A unique degradation process

Among insects, the larvae of theAlphitobius have a rather unique digestive system. The researchers identified specific bacteria in its intestine, including Proteobacteria and Firmicutes, capable of degrading complex synthetic materials. Other bacterial genera work in symbiosis with them: Kluyvera, Lactococcus and Citrobacter, capable of producing enzymes specialized in the digestion of plastics.

This ability is not innate and is the result of an evolutionary process: the insect's intestinal bacteria gradually adapt to this unusual diet, modifying their composition to optimize the degradation of plastic.

The life cycle of this remarkable insect extends over 8 to 10 weeks in the larval state. Although originally from Africa, the species has now spread worldwide, favoring warm, nutrient-rich environments such as chicken coops. The researchers also suspect that the strain studied could constitute a unique subspecies of the genus Alphitobius, a hypothesis currently under investigation.

An adult individual, belonging to the genus Alphitobius diaperinus after the stadium larval. © Udo Schmidt/Wikimedia Commons/CC BY-SA 2.0

Impressive performance under conditions

Experiments conducted over a month revealed that these larvae, when fed a mixed diet of wheat bran and polystyrene, managed to degrade 11.7% of the plastic ingested. This is why a balanced diet; i.e. not based solely on plastic; is necessary. Larvae fed only on plastic survive, but lose efficiency after a certain time. A complete nutrition is therefore required to optimize the degradation process.

The analysis of the digestive system of the larvae has highlighted quite significant variations in their bacterial composition according to their diet. This microbial plasticity explains their ability to adapt: polystyrene, composed mainly of carbon and hydrogen, provides them with a source of exploitable energy, even if it remains insufficient for their optimal development.

Towards an industrial solution?

As previously written, Africa is seriously affected by plastic pollution, a problem that can be explained by several factors. The continent is experiencing explosive population growth, which is leading to an increase in waste production that recycling infrastructures, often insufficient or non-existent, cannot contain.

Poverty leads many populations to use single-use plastic products, which are cheaper but more polluting. Conversely, the adoption of a “Western” lifestyle by certain communities, combined with an increase in purchasing power, leads to an increase in the consumption of products packaged in plastic. Finally, last but not least, Africa is sadly considered a “dustbin” for developed countries, which export their plastic waste there by the millions of tons.

Traditional recycling methods, such as chemical and thermal treatments, are costly and potentially polluting. This small insect could perhaps play an important role in this complex equation and researchers are considering use it as a natural depollutant. However, not just anyhow.

Rather than releasing these larvae into landfills, researchers plan to isolate the bacteria and enzymes responsible for the degradation to develop industrial solutions applicable to factories, landfills and decontamination sites. This biological approach could offer a more ecological and economical alternative to current techniques, while adapting to local constraints. Future research will focus on precisely identifying the bacterial strains involved and evaluating their potential for other types of plastics. Alphitobius may not have revealed all its secrets yet.

• A native African larva, the Alphitobius, can break down polystyrene thanks to specific bacteria in its gut.
• To effectively degrade plastic, these larvae require a mixed diet, including natural nutrients.
• Researchers hope to use these bacteria as an environmentally friendly alternative to traditional plastic recycling.

📍 To not miss any Presse-citron news, follow us on Google News and WhatsApp.

[ ]