‘Not all microbes are bad’: UCC lecturer on her beneficial bacteria research


14 Mar 2023

Visualisation of bacteria Streptococcus thermophilus. Image: © Dr_Microbe/Stock.adobe.com

Dr Jennifer Mahony cares about sustainable food production. She is researching bacterial viruses and their relation to food fermentation processes.

Dr Jennifer Mahony gets excited about the challenges of research.

Her PhD in molecular microbiology was about lactic acid bacteria genomics at University College Cork (UCC).

In 2021 she was appointed an associate professor of molecular food microbiology in the School of Microbiology, UCC, and a principal investigator in the APC Microbiome Ireland research centre. The research centre seeks to unravel how diet and human health coincide and to develop novel approaches to improving human health.

Mahony’s current work is dedicated to improving sustainable food production systems and to developing novel therapeutics in veterinary and human applications.

‘I have always been very curious about the natural world – wondering how and why things work the way they do.’

Jennifer Mahony

Dr Jennifer Mahony. Image: APC Microbiome Institute

Tell us about your current research.

Every day we consume fermented foods such as cheese, yogurt, salami and kefir as part of our diet. These foods are produced using beneficial microbes such as Lactobacillus and Streptococcus thermophilus in a process called fermentation.

If these bacteria do not grow optimally, the final product may not have the flavour or texture that we expect from that product. In addition, it may compromise the shelf-life and microbiological safety of the food product.

Bacteriophages are bacterial viruses that specifically infect certain bacteria. My research team are investigating how these bacteriophages recognise and infect the bacterium Streptococcus thermophilus and the ways in which bacteria can defend against such infections.

There is an ever-increasing demand for plant-based alternatives to dairy fermented products that retain the characteristics (flavour, texture, etc) of their dairy counterparts and this is a major challenge for the food industry.

My research team is exploring how we can adapt our understanding of dairy fermentation processes and the associated bacterial cultures to improve the quality and characteristics of vegan food products.

Why is your research important?

Every year, 16pc of dairy products are lost to food waste. This equates to 116m tonnes of dairy products and highlights the need for solutions to food waste.

The project that we are currently working on will help to establish how these bacteriophages infect their bacterial host and allow us to devise ways to prevent such infections from occurring, which in turn, will reduce the amount of food waste being generated.

While this research is critical to support the agri-food sector, the knowledge that we gain into the bacteriophage-bacteria interactions serve as a foundation to understand how bacteriophages interact with other bacteria, including pathogenic (or harmful) bacteria.

Bacteriophages are a ‘nuisance’ in food fermentations; however, in the context of infectious bacteria, bacteriophages present an opportunity to develop new and alternative therapies to replace or complement antibiotics.

What inspired you to become a researcher?

I have always been very curious about the natural world – wondering how and why things work the way they do. This led me first to study horticulture and then subsequently to study microbiology and food science.

During my undergraduate studies, I had the good fortune to do a summer placement in the laboratory of Professor Douwe van Sinderen at UCC and during this project I was introduced to bacteriophages.

I helped researchers perform experiments in the lab and understood what was involved in research. This experience and the challenge that it presented helped me to establish that a career in research was the route for me.

Do you think public engagement with science has changed in recent years?

Public engagement has changed dramatically in recent years and the pandemic has certainly shaped our view of science.

Indeed, during the pandemic, the importance of informing the public about microbes such as viruses, how they are transmitted and how our immune system responds to them, was central to our ability to ensure vaccine uptake by the public and improve personal hygiene practices.

I engage with companies who produce fermented foods and the bacterial cultures that are used in the fermentations to inform them of the risks of bacteriophages and how we may reduce this risk through improving culture selection and hygiene and sanitation practices in factories.

We also engage with primary and secondary school students to improve awareness of our research at all levels.

What are some of the biggest challenges or misconceptions you face as a researcher in your field?

Sometimes people are surprised (and even appalled!) to hear that certain foods have bacteria or fungi deliberately added to them.

These microbes that underpin the fermentation processes are beneficial and have been used for centuries in the production of a whole variety of fermented foods all over the world.

Not all microbes are bad!

In fact, in addition to helping us provide tasty, fermented foods, many of these microbes are beneficial to consume in foods or as ‘probiotic’ products and can play a role in aiding digestion, boosting our immune system and even produce vitamins to support our health.

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