Microbiome of Soils and Supraglacial Objects in Background and Oil Polluted Ecosystems Hayes Island (Franz Joseph Land Archipelago)

Abstract

Using luminescent microscopy and real-time PCR, the microbiome of soils and supraglacial objects in the background and oil-contaminated ecosystems of the island was studied Hayes Island, part of the Franz Josef Land archipelago. Biomass of microorganisms ranged from 81 to 666 µg/g of substrate; most of it (up to 88%) is represented by fungi. Length of fungal mycelium reached more than 360 m/g of substrate. The number of prokaryotes varied from 4.0 × 107 to 3.75 × 10⁹ cells/g of substrate; the length of actinomycete hyphae reached 40 m/g of substrate. Up to 78% of the detected prokaryotic cells are represented by small nanoforms, which is typical for extreme ecosystems. Share of viable cells of microorganisms is maximum (74–86%) for surface organogenic horizons and minimum (29–54%) for mineral suprapermafrost layers. Prokaryotic complex was dominated by bacteria (from 5.14×105 to 5.05 × 10¹⁰ 16S rRNA copies/g of soil), but not by archaea, from 8.46 × 10⁵ to 2.28 × 10⁹ 16S rRNA copies/g of substrate. Amount of FJL fungal genetic material ranged from 6.47 × 10⁴ to 8.67 × 10¹⁰ ITS rRNA copies/g soil. Number of copies of the alkB gene (synthesis of alkane monooxygenase for the destruction of hydrocarbon n-alkanes) varied from 1.2 × 10¹ to 1.8 × 10⁵/g of substrate and sharply decreased from the surface horizons to the deep ones. Oil-contaminated soils and supraglacial objects contained a smaller biomass, however, a greater number of ribosomal genes of microorganisms compared to the background ecosystems. An exponential decrease in the analyzed quantitative parameters of microorganisms from surface to deep soil horizons was registered.