Qualitative and Quantitative Characteristics of the Soil Microbiome in the Impact Zone of the Kandalaksha Aluminum Smelter

Abstract: The prokaryotic and fungal biomass was estimated by luminescent microscopy; the number of ribosomal gene copies of microorganisms was determined by the real-time PCR method, and the taxonomic diversity of culturable micromycetes in Albic Podzols was studied along the pollution gradient (1.5, 8, 15, and 50 km) from the Kandalaksha aluminum smelter, Kola Peninsula. In the soils of all sites, the largest number of ribosomal gene copies was found for bacteria (4.2 × 1010…10.3 × 1010 gene copies/g soil). For fungi and archaea, this number varied between 0.4 × 1010…3.1 × 1010 gene copies/g soil. There was a significant increase in the actinomycete biomass near the smelter, while the biomass of bacteria and fungi did not change at different distances from the source of emissions. Mycelium and spores of fungi were represented mostly by small forms with a diameter of 2–3 µm. In a heavily polluted area (8 km from the smelter), the proportion of spores was more than a half of the total fungal biomass, and the number of large spores was maximum (33.6%). The length of the fungal mycelium varied from 92.27 to 206.26 m/g, while there were no regularities in its distribution along the pollution gradient. There was a decrease in the diversity of soil micromycetes at the level of genera and higher taxa along the pollution gradient. The change in community structure from polydominant (background area) to monodominant (near the smelter) was found. Penicillium spinulosum dominated in all contaminated sites within the 15-km zone. In the background area, in addition to the above species, Trichoderma koningii, P. implicatum, and a group of fungi with sterile mycelium were among the dominants. © 2021, Pleiades Publishing, Ltd.