# Gas pipelines, highways for hydrogenotrophic spore-forming bacteria

## TL;DR

This paper explores hydrogenotrophic spore-forming bacteria found in gas pipelines and underground storage, revealing their role in biogeochemical cycles and energy systems.

## Contribution

The study identifies a resilient hydrogenotrophic bacterial species in gas infrastructure and highlights its potential impact on future hydrogen injection strategies.

## Key findings

- Endospores of Peptococcaceae bacteria were detected in high-pressure pipelines and underground reservoirs.
- These bacteria perform acetogenesis, biofilm formation, and formate production.
- Formate from these microbes can act as a carbon source or inhibit sulfate reduction.

## Abstract

A device capable of sampling natural gas under aseptic conditions and in complete safety has been deployed along the transmission grid for the first time. Microbial endospores, resilient enough to survive the extreme conditions of gas transmission and storage, have been detected and isolated throughout high-pressure pipelines and underground reservoirs. In four underground gas storage (UGS) facilities, three in deep aquifers and one in a depleted reservoir, endospores of the same hydrogenotrophic bacterial species from the family Peptococcaceae have been identified, sometimes separated by hundreds of kilometers, and at two different points in the pipeline network. Cultural and genomic analyses show these bacteria can perform acetogenesis, biofilm formation, and produce formate. Hidden within pipelines, these microbes survive long journeys and actively participate in biogeochemical cycles in UGS. Several recent studies on dihydrogen injection into deep aquifers have shown the ubiquity of bacteria similar to these, responsible for formate formation through modified acetogenesis. This formate can serve as a carbon source or inhibit sulfate reduction at high concentrations. Understanding their role offers critical insights into microbial life in the deep biosphere and the potential impacts of future dihydrogen injection into natural gas systems. Their ability to thrive in extreme environments makes these microbes key players in the evolving landscape of underground energy storage and transport.

Graphical Abstract