A recent study revealed that the cockroach Blaptica dubia can degrade up to 55% of polystyrene in 42 days, transforming part of that material into energy usable for its metabolism.
- Each specimen consumed about 6 mg daily of polystyrene.
- The process was not limited to fragmenting the plastic: oxidation and molecular chain breakage were observed, indicating a real depolymerization.
- The carbon from the plastic ended up integrated into metabolic pathways such as β-oxidation, the Krebs cycle, and oxidative phosphorylation, generating cellular energy.
Polystyrene is one of the most common plastics in everyday life: containers, food trays, protective packaging. Its low cost and practicality have made it an omnipresent material, but its chemical resistance makes it extremely difficult to degrade. When it fragments into microplastics, it can travel through entire ecosystems, accumulating in soils, rivers, and seas.
The Role of Microorganisms
The study showed that bacteria such as Pseudomonas, Klebsiella, and Citrobacter play a key role. These communities produce specific enzymes (oxidoreductases and transferases) that initiate the chemical attack on the polymer. It is a biological assembly line:
- The microorganisms break the material into manageable fragments.
- The cockroach utilizes the resulting compounds in its energy metabolism.
Biotechnological Implications
This finding does not mean that releasing cockroaches will solve the plastic crisis. The real value lies in understanding the system as a complex biological platform, where the following interact:
- Specialized microorganisms.
- Degrading enzymes.
- The host’s metabolism.
This approach aligns with a growing trend in biotechnology: instead of seeking a “magic enzyme,” the focus is on microbial consortia and combined metabolic pathways.
Potential Applications
If these processes are transferred to controlled environments, they could:
- Improve the chemical recycling of complex plastics that currently end up in landfills or incinerators.
- Reduce the accumulation of microplastics in aquatic and terrestrial ecosystems.
- Transform waste into energy resources or raw materials, partially closing the carbon cycle.
Risks and Challenges
Incomplete or poorly managed degradation could generate undesirable by-products, requiring further research to ensure safe and efficient processes. Additionally, transferring this system to an industrial scale involves designing nature-inspired bioreactors capable of replicating the interaction between insects, bacteria, and enzymes.
The discovery that cockroaches can degrade polystyrene and utilize it as energy opens a new perspective in the fight against plastic pollution. Beyond the anecdotal, this finding provides keys to developing advanced biological recycling technologies, capable of tackling one of the most persistent environmental problems of our time.
