Characteristics of the Prokaryotic Community in Arctic and Antarctic Soils Polluted with Petroleum Hydrocarbons

Abstract Polar soils and soil-like bodies (soloids) contaminated with petroleum hydrocarbons were studied using molecular biological (FISH, metabarcoding) and analytical methods. The objects of this study included prokaryotic communities of soloids of the Larsemann Hills Oasis in East Antarctica and of mucky and peaty gleyzems in the Eastern sector of Russian Arctic. The abundance of prokaryotes in the Eastern Arctic soil samples exceeded that in the Antarctic soloids by an order of magnitude; however, molecular genetic analysis revealed a greater number of bacterial genera potentially capable of oxidizing oil and oil products in the Antarctic soloids than in the Arctic soils. An inverse correlation (r = –0.91) was established between the amount of remaining petroleum hydrocarbons and the expression level of the functional alkB gene. The rate of utilization of petroleum hydrocarbons in the group of Antarctic soloids was higher than that in the Arctic soils. For each study area, the most resistant to oil pollution representatives of the bacterial community were identified. For Arctic soils, they included Pseudomonadota (Pseudomonas, Rudosibacter, Rhizomicrobium) and Actinomycetota (Nocardioides, Mycobacterium); for Antarctic soloids—Pseudomonadota (Marinobacter, Pseudomonas) and Bacteroidota (Sediminibacter, Gillisia). The obtained results on the abundance and taxonomic diversity of the prokaryotic community of the studied polar territories can be useful for developing efficient bioremediation strategies for oil-polluted areas.