Soil Microbiome in the Impact Zone of the Pechenganikel Plant Emissions (Murmansk Region)

The microbial parameters in Albic Podzol soil were analyzed along the pollution gradient (3, 16, 30, 50 km) with Pechenganickel plant emissions (Murmansk region). The amount and structure of the prokaryotes and fungi biomass were assessed by the method of luminescent microscopy; the content of microorganism’s ribosomal genes copies was determined by real-time PCR; the taxonomic diversity and abundance of culturable soil microfungi were studied. An increase in the number of genes copies of bacteria, archaea, and fungi close the source of emissions compared to remote areas was revealed. In all plots, the highest number of ribosomal genes copies was found for bacteria (from 3.21 × 1010 to 12 × 1010 per g of soil). For fungi and archaea, the number varied from 0.53 × 1010 to 1.59 × 1010 per g of soil and from 0.55 × 1010 to 11.41 × 1010 gene copies/g of soil, respectively. A significant increase in the actinomycetes biomass close the plant was noted, while the biomass of bacteria and fungi remained practically unchanged at different distances from the emission source. Mycelium and fungal spores in all areas are mainly represented by small forms with a diameter of 2–3 microns. The length of the fungal mycelium varied from 51.2 m/g near the plant to 397 m/g in remote areas, with no regularities in its distribution along the contamination gradient. A decrease in the diversity of soil microfungi at the level of genera and higher taxa along the pollution gradient with plant emissions was noted. A change in the structure of communities from polydominant (background site) to monodominant (near the plant) was revealed. The species Penicillium raistrickii dominated in all plots. Fungi Trichoderma viride, dark-colored yeasts Torula lucifuga (3 km) and Aureobasidium pullulans (16 km) also dominated in the zone 16 km from the emission source. In the background area, representatives of the orders Mucorales and Umbelopsidales were dominant.