Rhodothermus bifroesti sp. nov., a thermophilic bacterium isolated from the basaltic subsurface of the volcanic island Surtsey

Scientists have discovered a novel thermophilic bacterium, Rhodothermus bifroesti sp. nov., in the basaltic subsurface of Surtsey, a volcanic island off Iceland's south coast. This Gram-negative, rod-shaped microorganism thrives at 70°C and exhibits distinct genetic traits, setting it apart from its closest relatives with only 17.6% digital DNA–DNA hybridization similarity to Rhodothermus marinus and 16.9% to Rhodothermus profundi. The bacterium was isolated from tephra core and borehole fluid samples collected below 70 meters depth, highlighting the unique microbial diversity in extreme environments. Comparative chemotaxonomic, genomic, and phylogenetic analyses confirmed its status as a new species within the genus Rhodothermus.

Bergsten, P., Vannier, P., Mougeolle, A., Rigaud, L., & Marteinsson, V. T. (2022). Rhodothermus bifroesti sp. nov., a thermophilic bacterium isolated from the basaltic subsurface of the volcanic island Surtsey. International Journal of Systematic and Evolutionary Microbiology, 72(1). https://doi.org/10.1099/ijsem.0.005214