Wastewater treatment plants (WWTPs) face increasingly stringent nutrient discharge standards to protect environmental water bodies and human health. Poly-phosphate accumulating organisms (PAOs) are microbes that mediate enhanced biological phosphorus removal (EBPR). PAO are however often outcompeted by glycogen accumulating organisms (GAOs), limiting total phosphorus removal. Previous research has identified a link between GAO abundance and elevated wastewater temperature. Current control mechanisms for limiting GAO require physical or chemical process alterations. However, these alterations have been shown to limit the performance of other aspects of biological nutrient removal (BNR) and enhance nitrogen-based greenhouse gas (GHG) emissions. With the advent of rising global temperatures more regions globally are expected to operate with elevated levels of GAO competition. In addition, some WWTPs already operate at elevated temperatures due to geographical location, seasonal temperature variations and/or heat-treated trade wastewater influent.

We aim to develop a novel bacteriophage-based approach that triggers lysis of GAO as a biological control mechanism for limiting competition between these organism groups. Additionally, with the advent of newly developed targeted genome editing tools, particularly DNA-editing all-in-one RNA-guided CRISPR-CAS transposase (DART), we are exploring new approaches for biological control and enhancement to improve EBPR efficiency. Collectively, this research will demonstrate how biological tools and control mechanisms can be a feasible approach for biofilm community editing and enhancement of WWTP performance.