New method harnesses solar-powered biofilms to eliminate soil pollutants

New method harnesses solar-powered biofilms to eliminate soil pollutants
by Clarence Oxford
Los Angeles CA (SPX) Oct 25, 2025

Recent research has demonstrated that iron mineral-bacterial biofilms can effectively degrade environmental contaminants by leveraging solar energy. This novel approach not only enhances the breakdown of antibiotics such as tetracycline hydrochloride and chloramphenicol, but also presents a major advancement for sustainable pollution control and bioremediation.

Scientists have discovered that non-phototrophic microbes in soil can utilize sunlight through mineral-microbe interactions, expanding the recognized impact of solar energy beyond photosynthesis. By exploiting the interplay between iron minerals and bacteria, researchers have developed biofilms with charge-storage capabilities, enabling pollutant mitigation even in soil zones where light is limited.

A study published in Environmental and Biogeochemical Processes on September 15, 2025, by teams from Kunming University of Science and Technology and the University of Massachusetts, introduces an efficient and scalable strategy for cleaning polluted soil and groundwater. The research focused on the interaction between iron oxide minerals and Bacillus megaterium bacteria, revealing a system capable of accumulating and releasing electrons during alternating light and dark cycles. The charge storage mechanism was more effective with higher bacterial density and additional light exposure.

Crucially, the system demonstrated a measurable photovoltage memory effect and a continuous function similar to a biological capacitor. This resulted in marked improvements in pollutant degradation efficiency, with tetracycline hydrochloride and chloramphenicol breakdown increasing by 66.7 percent and 46.7 percent respectively following targeted light exposure. This enhanced efficiency was linked to electron transfer and storage within the biofilm structure, confirmed by both structural and electrochemical analysis.

The bio-photovoltage biofilm system provides a promising solution for environmental restoration, offering pollution control that continues without the need for constant illumination. Its capacity to store solar energy and then release it for contaminant degradation makes it an innovative option for remediating antibiotic contamination in soils and groundwater.

Research Report:A bio-photovoltage soil-microbe battery for antibiotic degradation in the dark