Hydrogel-based delivery of predatory bacteria for biofilm control in water treatment systems
Supervisor: Dr Ayo Ogundero
School: Engineering
Description:
Approximately 10% of Scottish water treatment works serve 90% of Scotland’s rural population, highlighting the fragmented nature of rural water infrastructure and the need for decentralised treatment solutions. Conventional centralised treatment systems are often impractical in these settings due to high capital, energy, and maintenance requirements. As a result, there is increasing reliance on small-scale technologies such as membrane filtration. However, their widespread implementation is constrained by membrane biofouling, driven by the growth of bacterial biofilms. Biofilm accumulation reduces permeability, increases energy demand, and shortens operational lifespan, ultimately limiting system efficiency. Current control strategies rely heavily on chemical interventions such as chlorination, which require continuous dosing and can promote antimicrobial resistance and the formation of harmful disinfection by-products, making them less suitable for resource-limited environments.
The predatory bacterium Bdellovibrio bacteriovorus has emerged as a promising biological alternative, capable of targeting a wide range of biofilm-forming bacteria, including Pseudomonas aeruginosa. Its application against biofilm growth has been explored in many fields including clinical therapy, agriculture and water treatment. However, despite this potential, its practical application remains limited by the lack of strategies to control and sustain predator populations within engineered systems. In particular, maintaining effective predator concentrations over time remains a key barrier to deployment.
This project will evaluate 2NapFF hydrogel “noodles” as a controlled delivery platform for predatory bacteria. By enabling sustained release, hydrogels offer the potential to enhance predator persistence and stabilise predation dynamics, overcoming a major limitation of direct inoculation approaches. Understanding and quantifying this effect is critical for translating predatory biocontrol strategies into practical engineering solutions.
The project will quantify prey growth, predation dynamics, hydrogel release kinetics, and predator persistence using flow cytometry, enabling the derivation of key mathematical parameters including growth, predation, decay, and release rates. These experimentally derived parameters will be integrated into a predator–prey mathematical model to simulate microbial dynamics under different conditions and provide insight into how delivery strategies influence system performance.
Ultimately, this project will establish quantitative design principles for hydrogel-mediated delivery of predatory bacteria, providing a foundation for the implementation of biological biofilm control strategies in decentralised membrane-based water treatment systems.