Important role of prokaryotic viruses in sewage treatment uncovered

Clinically, phage therapy has been demonstrated by other research team as an effective way against the antibiotic resistant superbug Acinetobacter baumannii, and activated sludge in WWTPs is an important source for isolating phages for treating infections to save people's lives.

The research team led by Professor Tong Zhang in the Department of Civil Engineering at the University of Hong Kong (HKU) recently applied a systematic metagenomic pipeline to retrieve a catalogue of around 50,000 phages from six WWTPs in Hong Kong. The study reveals the large and uncharacterised prokaryotic viral diversity in activated sludge, and largely expands the current AS prokaryotic virus catalogue to provide reference for utilising phage treatments to control undesired microorganisms in WWTPs. The findings have been published in leading science journal Nature Communications.

Professor Zhang said: "Prokaryotic viruses are so small that people overlooked the roles of them in WWTPs. By uncovering the extensive virus-host interactions in functional microorganisms in WWTPs, this study highlights the potential roles of phages in pollutant removal and environmental protection."

This is the first work globally to explore the connections between functional microorganisms in WWTPs and prokaryotic viruses. Future work will include analysing the dynamics of the phage community of AS in the long term and isolating phages to control undesired bacteria in WWTPs.

This work is a part of Professor Zhang's project supported by the University Grants Committee's Theme-based Research Scheme (TRS) aimed at supporting research of strategic importance.