Engineering a capture-bioremediate-release microbial biofilm for simultaneous bioremediation of microplastics and...

Microplastics (MPs) pose escalating environmental and human health risks, particularly when they adsorb heavy metals and form complex, co-contaminated pollutants. Furthermore, when MPs are removed and sent to landfills or incineration, the adsorbed heavy metals often persist and re-enter the environment. However, most existing remediation strategies remove only single pollutants, which fail to address complex pollution. In this research article, we engineered an environmental Pseudomonas aeruginosa strain with three programmable functions: (i) enhanced biofilm formation for efficient aggregation and capture of MPs, (ii) increased pyoverdine production for bioremediation of heavy metals (lead and cadmium) adsorbed on MPs, and (iii) subsequent arabinose-inducible biofilm dispersal to release decontaminated MPs for convenient recovery. Our proof of concept was validated in a pilot trial with polluted Hong Kong seawater, demonstrating efficient dual-pollutant removal in environmentally relevant conditions. Hence, our work highlights the promise of biotechnology in advancing multi-pollutant environmental remediation.