Algae that eliminates microplastic?
Scientists have engineered a remarkable strain of algae that hunts down microplastics — and it smells like oranges.
Microplastics are virtually everywhere — in rivers, lakes, drinking water, and even the fish on your plate. For years, removing them has seemed like an impossible task. Now, a researcher at the University of Missouri may have found an elegantly natural answer to a very unnatural problem.
Professor Susie Dai and her team have genetically engineered a new strain of algae that actively attracts and captures microplastics from contaminated water. The innovation, published in Nature Communications, works by exploiting a surprising chemical property — and it just might transform how cities treat their water.
The Problem Slipping Through the Cracks
Modern wastewater treatment plants are effective at removing large debris and pathogens, but microplastics are a different story. Too tiny for conventional filtration to catch, they slip right through and make their way into waterways, ecosystems, and ultimately our bodies. They’ve been detected everywhere from deep ocean trenches to Arctic ice — and in tap water, bottled water, and seafood.
An Orange-Scented Solution
Dai’s breakthrough centers on limonene — the same compound that gives orange peels their zesty scent. By genetically engineering algae to produce limonene, she made the algae’s surface water-repellent. Since microplastics are also water-repellent, the two are drawn together like magnets when they meet in water, clumping together and sinking to the bottom where they can easily be collected.
The engineered algae can grow directly in wastewater, feeding on excess nutrients as it works — meaning it cleans the water simply by doing what algae do naturally.
“By removing the microplastics, cleaning the wastewater and eventually using the removed microplastics to create bioplastic products for good, we can tackle three issues with one approach.” — Prof. Susie Dai
Thinking Big
Dai’s lab already runs a 100-liter bioreactor nicknamed “Shrek,” and the goal is to scale the technology up for integration into existing municipal water treatment plants. Even more ambitiously, she envisions repurposing the collected microplastics into functional bioplastic products — turning pollution into a resource rather than just a problem to be stored away.
The research is still in early stages, but in a world saturated with plastic waste, a living, growing, citrus-scented solution is a genuinely hopeful sign.
Based on research from the University of Missouri, published in Nature Communications (2025).
This topic was featured in Great News podcast episode 34.
Source: Futurity | University of Missouri
