Persistent Petroleum Pollution: Microbial Responses in Bunger Hills, East Antarctica

Microbes in hyper-arid and oligotrophic ecosystems like Antarctica, rely on atmospheric trace gas oxidation for survival using high-affinity enzymes to generate energy for critical ecological processes including primary production, persistence, and carbon mitigation. Hydrocarbon contamination, common around Antarctic research stations, disrupts microbial communities, yet its implications for trace gas oxidation and dark carbon fixation are unknown. Here, we show the soil microbial diversity of Bunger Hills, East Antarctica, and assessed the response of a 40-year-old legacy petroleum spill on microbial communities and their functions. Metagenomic analysis and gas chromatography revealed significant shifts in microbiome composition and function in contaminated soils alongside severely reduced hydrogen oxidation rates, but higher (¹⁴CO₂) carbon fixation rates. We assembled 300 metagenome-assembled genomes across 16 bacterial and archaeal phyla, identifying 25 novel candidate species. We demonstrate long-lasting effects of pollutants on microbial ecosystems and services in polar regions, highlighting the role of trace gas scavengers and hydrocarbon degraders in regulating key ecological functions and advancing knowledge of anthropogenic impacts on microbial nutrient and energy acquisition in dry desert environments.