Microalgae Break Down Ulcer Drug in Wastewater, Study Shows

Scientists have discovered that a type of microalgae can break down cimetidine, a common ulcer medication, in wastewater. This drug is hard to remove using regular treatment methods, which means it ends up polluting water systems.

The research focused on a strain called Chlamydomonas sp. SI-16, found in municipal wastewater. This microalga showed strong ability to handle high levels of the drug. In lab tests, it removed about 82% to 83% of cimetidine when exposed to concentrations of 1, 5, and 10 mg per liter.

When the algae were exposed to higher doses of the drug, their natural defense systems kicked in. They produced more antioxidant enzymes and released substances that protect cells. These responses helped the algae survive and keep breaking down the medication.

The main mechanism behind this breakdown involves an enzyme called cytochrome P450 (CYP450). Tests using enzyme blockers and computer modeling confirmed this enzyme plays a key role in processing the drug.

In real wastewater samples, the algae removed 95.5% of cimetidine within 24 days. A control sample without algae only removed 66%. Tests with tiny worms showed the leftover material was much less toxic after the algae treated it.

Researchers also tested a simple system using algae attached to ropes in a tank. This setup removed 78.6% of the drug, showing the method could work outside the lab. This approach offers a new way to clean pharmaceuticals from wastewater using natural biological processes.