Abundance and Diversity of Prokaryotic Communities of Dust Aerosol and Urban Soils in the Territory of Moscow

A comprehensive quantitative and qualitative characterization of prokaryotic communities of solid atmospheric fallout (dust aerosol) and soils in the areas with different anthropogenic loads within the territory of Moscow was obtained. The total number of bacteria in the studied samples of solid atmospheric fallouts (SAF) was lower than the number of bacteria in soil samples; actinomycete mycelium was not found in dust samples, although it was found in soil samples. The number of culturable saprotrophic bacteria in dust samples was an order of magnitude lower than in Urbic Technosols taken at the same plots. Representatives of the genus Micrococcus dominated the culturable bacteria in the dust aerosols, while representatives of the phylum Proteobacteria dominated in soils. Representatives of the Enterobacteriaceae family were found in the dust samples, among which there were species that are potential human pathogens. The maximum biodiversity of bacteria of the Enterobacteriaceae family was recorded in the dust samples taken in areas with increased anthropogenic and transport load. The sanitary-indicative bacterium Escherichia coli was found in all samples of the dust and Urbic Technosols; its content varied from 10 to 100 CFU/g, which corresponds to the moderate degree of epidemic danger. Ecological indices calculated for prokaryotic communities in situ (barcoding of the 16S rRNA gene) indicate a lower taxonomic diversity of SAF prokaryotic communities in comparison with communities of closely spaced Urbic Technosols.