Participant Detail

Research Title

Protecting the Han River from Pharmaceuticals: Indigenous Bacteria-Mediated Metformin Degradation

Research Abstract

The Han River is a critical source of freshwater for millions of residents in the region. However, widely prescribed medications such as antidiabetic and antihyperlipidemic drugs have been detected in its waters, posing significant environmental and health risks. Conventional purification systems fail to remove these compounds, leading to their accumulation and harmful effects on aquatic ecosystems and human health. This study investigated the presence of metformin-degrading bacteria in the Han River and its tributaries to develop a sustainable method of water purification that does not lead to secondary pollution. Ammonia reduction was used as an indicator of metformin degradation, and among 38 isolated bacterial strains, 5 showed strong degradation capacity. Three strains also demonstrated effectiveness against rosuvastatin calcium, an antihyperlipidemic drug. Species identification through 16S rRNA gene sequencing revealed two highly efficient degraders: Novispirillum itersonii and Undibacterium oligocarboniphilum. These bacteria were immobilized on stones to ensure stable establishment in the river, and purification performance was validated with 89.1% accuracy using machine learning–based predictive modeling (Random Forest). The findings indicate that U. oligocarboniphilum applied to a smooth rock is the most effective combination for metformin degradation, offering an eco-friendly and sustainable bioremediation strategy for reducing pharmaceutical pollution in freshwater environments.