A groundbreaking study into underground microbes that could influence hydrogen storage in Aotearoa is being conducted by University of Canterbury (UC) Microbiology PhD student Kelsey McKenzie

She began her research in 2023, is investigating microorganisms found in water samples extracted from deep underground oil and gas reservoirs in Taranaki. Early results suggest microbial communities in Aotearoa differ significantly from those in similar reservoirs worldwide, she said.

"The goal is to carry out genome sequencing so we can find out more about the microbes’ DNA, and how they behave and react when exposed to hydrogen," McKenzie said.

Her research is part of a five-year UC-led project funded by the Ministry of Business, Innovation and Employment’s Endeavour Fund. The initiative aims to reduce carbon emissions and explore options for underground hydrogen storage in Aotearoa.

Hydrogen is widely regarded as a key component in the transition away from fossil fuels towards sustainable energy. However, storing large quantities of the gas remains a challenge for researchers.

Some underground microbes thrive in hydrogen-rich environments and use the gas as an energy source, McKenzie said. "This work will help us understand how these organisms would interact with hydrogen before we start pumping hydrogen into their environment."

The microscopic organisms she is studying belong to a group known as "extremophiles" because they can survive and thrive in extreme conditions, including minimal oxygen, high pressures, and temperatures above 80 degrees Celsius.

Genome sequencing is revealing vital traits about how these microorganisms interact with hydrogen. McKenzie has already found that some have genes capable of both utilising and creating hydrogen. "Studying the DNA of these microorganisms will tell us broadly speaking what’s down there, what kinds of species there are, what kind of genes they have, and what they can do," she said.

She has been cultivating the microorganisms in a UC laboratory for future experiments.

"It’s a really nice mix of analysing and sequencing data and doing work in the lab. It’s an awesome project to be a part of and it’s really exciting that this is the first time it has been done in New Zealand," McKenzie said.

UC School of Biological Sciences Professor Matthew Stott, who is supervising McKenzie’s research, said there can be up to 100,000 microorganisms in just one millilitre of water.

"There’s a lot of life down there in these oil and gas reservoirs – billions and billions of bacteria – so it’s important to find out what the impact and consequences would be of using these kinds of spaces to store hydrogen in the future," Professor Stott said.

"If we know what the likely consequences will be, then we can take steps to mitigate them. We hope this research will contribute to the global effort towards progressing underground hydrogen storage and promoting green energy sources."