Scientists at NTU & SCELSE develop artificial ‘worm gut’ for upcycling of plastic wastes

A team of scientists from SCELSE at Nanyang Technological University, Singapore (NTU Singapore) has developed an artificial ‘worm gut’ to break down plastics, offering hope for a nature-inspired method to tackle the global plastic pollution problem. By feeding worms with plastics and cultivating microbes found in their guts, researchers from NTU’s School of Civil and Environmental Engineering (CEE) and SCELSE have demonstrated a new method to accelerate plastic biodegradation.

Previous studies have shown that Zophobas atratus worms – the larvae of the darkling beetle commonly sold as pet food and known as ‘superworms’ for their nutritional value – can survive on a diet of plastic because its gut contains bacteria capable of breaking down common types of plastic. However, their use in plastics processing has been impractical due to the slow rate of feeding and worm maintenance.

SCELSE scientists have now demonstrated a way to overcome these challenges by isolating the worm’s gut bacteria and using them to do the job without the need for large scale worm breeding.

Developing an artificial worm gut

To develop their method, the NTU scientists fed three groups of superworms different plastic diets – High-density polyethylene (HDPE), Polypropylene (PP) and Polystyrene (PS) – over 30 days. The control group was fed a diet of oatmeal. The scientists selected the plastics as they are among the most common plastics in the world, used in everyday items like food boxes and detergent bottles. HDPE is a type of plastic known for its high-impact resistance, making it difficult to break down.
After feeding the worms plastic, scientists extracted the microbiomes from their gut and incubated them in flasks containing synthetic nutrients and different types of plastics, forming an artificial ‘worm gut’. Over six weeks, the microbiomes were left to grow in the flasks at room temperature.

The researchers say their proof-of-concept lays the foundation for developing biotechnological approaches that use worms’ gut microbiomes to process plastic waste. For their next steps, the researchers want to understand how the bacteria in the superworm’s gut break down the plastics at the molecular level. Understanding the mechanism will help scientists engineer plastic-degrading bacterial communities to break down plastics efficiently in the future.

Read the press release.