2017/12/01 by Mukan Ji, Chris Greening, Inka Vanwonterghem +11 · 4 citations
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Microbial Community Ecology and Physiology #Photosynthetic Processes and Mechanisms #Polar Research and Ecology
paper · pdf · doi:10.1038/nature25014
openalex publication_date 2017/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Metagenomic and biochemical analyses of soil samples from Antarctic desert regions provides evidence that bacteria in these soils derive carbon and energy from atmospheric CO, H2 and CO2. Terrestrial Antarctica is one of the most extreme environments on Earth, but previous work has shown that it does support microbial life. How microbial communities sustain their energy and carbon needs at sites at which photosynthetic potential is low has been unclear. Belinda Ferrari and colleagues applied shotgun metagenomics and biochemical analyses to clarify the basis of primary production in two such Antarctic sites, and demonstrate that the atmospheric trace gases H2 and CO are oxidized at rates sufficient to sustain these communities. This represents a novel mode of primary production, but further work is required to evaluate whether it is a widespread pathway for energy generation. Cultivation-independent surveys have shown that the desert soils of Antarctica harbour surprisingly rich microbial communities1,2,3. Given that phototroph abundance varies across these Antarctic soils2,4, an enduring question is what supports life in those communities with low photosynthetic capacity3,5. Here we provide evidence that atmospheric trace gases are the primary energy sources of two Antarctic surface soil communities. We reconstructed 23 draft genomes from metagenomic reads, including genomes from the candidate bacterial phyla WPS-2 and AD3. The dominant community members encoded and expressed high-affinity hydrogenases, carbon monoxide dehydrogenases, and a RuBisCO lineage known to support chemosynthetic carbon fixation6,7. Soil microcosms aerobically scavenged atmospheric H2 and CO at rates sufficient to sustain their theoretical maintenance energy and mediated substantial levels of chemosynthetic but not photosynthetic CO2 fixation. We propose that atmospheric H2, CO2 and CO provide dependable sources of energy and carbon to support these communities, which suggests that atmospheric energy sources can provide an alternative basis for ecosystem function to solar or geological energy sources8,9. Although more extensive sampling is required to verify whether this process is widespread in terrestrial Antarctica and other oligotrophic habitats, our results provide new understanding of the minimal nutritional requirements for life and open the possibility that atmospheric gases support life on other planets.