The majority of environmental bacteria exist in a dormant state, though questions still remain as to how they are able to downregulate their typical metabolic pathways in favour of alternative energy sources. A combination of environmental pressures coupled to low organic carbon availability, often leads to a competition for resources, resulting in the evolution of metabolic flexibility. More recently, research has discovered that previously characterised metabolically inflexible bacteria were able to utilise a range of alternate energy sources including harnessing the energy within atmospheric gases. In addition to meta-omics based findings, resolving the capacity for ecologically and phylogenetically distinct microorganisms using culture-dependent approaches is required to gain a holistic understanding of trace gas scavenging. We demonstrated the first axenic evidence of trace gas utilisation in cultivated thermophilic members of the phylum Chloroflexota using a group 1h [NiFe]-hydrogenase and highlight that this phenomenon is likely to be a main driver for environmental bacteria persistence, particularly for those residing in extreme ecosystems. Additionally, to determine whether additional variants of hydrogenases, such as the group 2a [NiFe]-hydrogenase, were capable of mediating atmospheric hydrogen oxidation, we experimentally validated the hydrogen scavenging ability of three environmentally and phylogenetically distinct species, Gemmatimonas aurantiaca, Acidithiobacillus ferrooxidans and Chloroflexus aggregans. We further extend this finding to marine ecosystems by demonstrating that the polar ultramicrobium, Sphingopyxis alaskensis, can mixotrophically grow on atmospheric hydrogen, suggesting that trace gas scavenging influences the biogeochemistry and ecology of global oceans. Concomitantly, our findings validate genomic surveys of potential trace gas oxidisers, provides pure culture evidence to complement ecosystem-based analyses and expands the number of bacteria experimentally validated to oxidise atmospheric concentrations of hydrogen. The characterisation of this phenomenon in diverse and abundant environmental bacteria suggest that the capacity for atmospheric gas oxidation is more widespread than previously thought and highlights the propensity for atmospheric gas utilisation as not only a viable persistence strategy, but also potentially for mixtrophic growth.