Published on 16 Jan 2023

Tiny organisms with a big impact

Assoc Prof Janelle Thompson investigates environmental microorganisms to engineer a sustainable future.

COVID-19 wastewater surveillance

Although tiny, microorganisms play key roles in helping us achieve sustainable development. For example, viral pathogens in wastewater can serve as an early warning of disease outbreaks, allowing us to contain the spread of infectious diseases in communities. We can also use microorganisms to produce sustainable compounds such as environmentally friendly fuels and valuable chemicals.

Currently, I am developing sensitive molecular methods to detect pathogens in wastewater. I am also interested in

developing new approaches for using extremophilic microbes – microorganisms that thrive under extreme environmental conditions – to produce sustainable chemicals and biofuels.

Detecting emerging diseases in wastewater

The COVID-19 pandemic has highlighted the importance of detecting pathogens circulating in the community early, so as to control the spread of infectious diseases and limit fatalities. 

Wastewater contains bodily discharges, which can include the SARS-CoV-2 virus and other pathogens from infected individuals that reveal the presence of infectious diseases in the community. Compared to nasal swabs, wastewater surveillance is a non-invasive method of detecting such disease-causing microorganisms. Because this method detects viral particles shed by both infected symptomatic and asymptomatic individuals, it is also an effective community surveillance strategy for COVID-19.

In collaboration with scientists from international and local institutes as well as public agencies in Singapore, my team and I have developed an approach for monitoring and detecting SARS-CoV-2—the virus that causes COVID-19—in wastewater. Using a sensitive molecular biology technique called reverse transcription-quantitative polymerase chain reaction (RT-qPCR), we are able to quantify the number of SARS-CoV-2 viruses in wastewater samples collected from community sewers and wastewater treatment plants.

These findings have supported the National Environment Agency’s launch of a nationwide wastewater surveillance programme to detect SARS-CoV-2 from wastewater in Singapore. In addition, we have developed methods to track SARS-CoV-2 variants of concern, analysed wastewater trends at a systems level and considered the broader societal implications of integrated wastewater surveillance.

Our research has also extended beyond COVID-19 with the application of integrated wastewater-based surveillance to the tracking of viruses like the dengue virus and the identification of new threats from yet unknown emerging diseases.

Producing sustainable chemicals and fuels

In my new laboratory at NTU, my team and I are discovering the biotechnological applications of extremophilic

microorganisms that live in harsh environmental conditions like extreme temperatures or high salt concentrations. These microorganisms have uniquely adapted to live in their extreme habitats. For example, some bacteria produce compounds that help them survive high temperatures, such as enzymes that are stable in extreme heat, making them of interest for industrial purposes.

To this end, my team and I are developing microorganisms like Bacillus megaterium SR7, which can tolerate highly

pressurised carbon dioxide inhospitable to most other microorganisms, for the production of environmentally friendly biofuels and valuable bioproducts.

Using mathematical and experimental approaches, we hope to gain in-depth insight into how Bacillus megaterium SR7’s metabolism changes under high pressure carbon dioxide, with the ultimate aim to improve the microorganism’s biofuel production capabilities.

In another project, we are characterising the previously unexplored microbial diversity at the Sembawang Hot Spring Park in Singapore. By analysing nucleic acids in the environment to trace the source of microbes in the geothermal water of the park, we hope to reveal the hidden microorganisms that grow in Singapore’s hot springs and uncover their potential industrial applications.

I am confident that understanding these fascinating microorganisms will open new avenues for us to lead more sustainable lives in the future.

By Janelle Thompson

Details of the research in this article can be found in Environmental Science & Technology Letters (2021), DOI:; Environmental Science & Technology Letters (2021), DOI: 10.1021/acs.estlett.1c00375; and Nature Communications (2019), DOI: 10.1038/s41467-019-08486-6.

The article appeared first in NTU's research & innovation magazine Pushing Frontiers (issue #20, June 2022).