Hydrogen From Living Rock

Vahid Mortezaeikia’s research begins with an observation that most scientists have overlooked. Countless studies of subsurface energy systems have examined microorganisms that consume hydrogen - organisms relevant to assessing storage stability and reservoir chemistry. Vahid is looking in the opposite direction: at the microorganisms that produce hydrogen, rather than those that consume it.

It is a subtle but consequential distinction, and it sits at the heart of his current work at DTU Offshore, where he is a postdoctoral researcher splitting his time between computational modelling and hands-on laboratory work at DTU BRIGHT. His research is part of the project BioHyPro, funded by Danmarks Frie Forskningsfond (DFF).

Before joining DTU Offshore, Vahid worked in industrial refinery operations and R&D in waste-to-energy system design, later extending his focus to hydrogen technologies, CO₂ management, and life cycle assessment.

An Early Signal

The work has already produced observations that were neither expected nor initially sought. In mapping the metabolic pathways through which the target microorganisms produce hydrogen - one of the project's core scientific goals - Vahid has found indications that go beyond the original scope of the research.

Among these is an indication that fermentative microorganisms isolated from subsurface environments may themselves contribute to sulfide transformation, leading to hydrogen sulphide (H₂S) formation. Conventionally, H₂S generation in such systems has been primarily associated with sulfate-reducing bacteria. This observation suggests that hydrogen-producing microorganisms may play a more complex role in sulphur cycling than previously recognised, a point that remains under investigation.

“I am optimistic,” he says. “Some of the most interesting insights come from exploring beyond the initial scope of a project. They can open pathways not only toward hydrogen production, but also toward other valuable products in the future.”

From Controlled Systems to the Geological Deep

The biological process at the centre of Vahid's research is dark fermentation, in which microorganisms convert organic compounds into hydrogen gas. While this process is well established under controlled laboratory and industrial conditions, it typically relies on simple, well-defined substrates. What Vahid is investigating is whether microorganisms originating from subsurface environments - where conditions are far more complex - can be adapted to perform the same function using compounds present in geological formations, including mixed organics and hydrocarbons.

“In conventional fermentation systems, simple substrates are usually applied,” he explains. “Here, we are investigating whether microorganisms can adapt to more complex organic mixtures, or even hydrocarbons, to produce hydrogen. That is the gap in the literature we are trying to address.”

The implications extend well beyond the laboratory. If hydrogen-producing microorganisms can survive and function under subsurface conditions, it raises the possibility of repurposing existing oil and gas infrastructure as large-scale biological systems, producing clean energy carriers from the same geological formations once used for fossil fuel extraction.