SRA

We report the widespread metabolic capacity for lithoautotrophy (gaining carbon and energy from inorganic sources) in the microbial community of termite mounds, sustained by termite hydrogen emissions. This unique example of interspecies hydrogen transfer across habitats creates a niche for an ancient metabolic trait and offers a new perspective in the important role of termites as ecosystem engineers. The remarkable enrichment of hydrogen-oxidising bacteria with high capacity to consume atmospheric hydrogen contrasts the low numbers of methane oxidisers and the limited filtering capacity of mounds to mitigate global termite methane emissions. Hydrogen thus appears to be a preferred substrate that strongly shapes soil microbial communities, which warrants consideration when transferring to a hydrogen-based economy.