Targeted Pathogen Control in Drinking-Water Biofilters
Supervisors:
Dr Giusy Mariano, School of Infection and Immunity
Prof Cindy Smith, James Watt School of Engineering
Summary:
Biofilters sustain the beneficial microbes that clean drinking water; however, they also promote opportunistic pathogens persistence. Chlorination is effective for bulk disinfection, yet it cannot be applied within biofilters without damaging the beneficial communities. As a result, pathogens such as Pseudomonas, Enterococcus, non-tuberculous Mycobacterium, and Legionella may persist.
Bacteriophages (phages) kill bacteria, while bacteria counter with diverse anti-phage systems (e.g. CRISPR-Cas, abortive infection). This arms-race shapes microbial communities across environments, including water treatment filters.
This project will test phages as a practical, biofilter-friendly alternative to chlorination. Bringing together metagenomics, phage discovery, and realistic lab columns/mesocosms, it will explore whether targeted phage treatments can remove persistent pathogens without harming biofilter performance. We will track long-term shifts in the resident community, quantify how bacterial anti-phage systems influence success and resistance, and compare dosing strategies to learn when intervention helps.
At completion, the project will provide fundamental insights into how phage–host conflicts shape microbial community stability in drinking-water treatment. It will provide depth-resolved ecological baselines, effective phage combinations, and time-aware dosing and monitoring rules that minimise resistance in pathogens while preserving water quality. Beyond immediate application, the project will not only inform sustainable pathogen control but also provide broadly applicable principles for phage–microbiome interactions in complex environments.