Local Monitoring of Saprotrophic Bacterial Complexes of Urban Soils in Syktyvkar in 2019 and 2020

Abundance and diversity of cultivated bacteria in saprotrophic soil complexes were monitored for two years on the territory of one of the large industrial cities of the European North of Russia, Syktyvkar. The analysis was carried out before and after quarantine due to the COVID-19 pandemic. The city of Syktyvkar is characterized by a high population and intensive anthropogenic pressure. According to the total indicators of the current state of the environmental components, it should belong to the tense category, by environmental standards. Studies were conducted in 2019–2020. Topsoils (0–10 cm) of urbanozems and horizon A in the park area in the urban space, as well as zonal undisturbed podzolic soil, were analyzed. Comparison of the two-year monitoring results demonstrated a marked increase in the number and diversity of saprotrophic bacterial complexes in 2020 in both urban and control soils (topsoil, 0–10 cm). Due to a sharp and prolonged decrease in the anthropogenic impact on the environment during quarantine measures, content of the bacteria of the families Enterobacteriaceae including sanitary-indicative ( Escherichia coli , Enterococcus faecalis ) and opportunistic and allergenic ( Enterobacter agglomerans , Citrobacter europaeus , Klebsiella oxytoca , Serratia marcescens , etc.) in the urbanozems decreased. This can be considered as a manifestation of the soil’s ability to “self-remediate” during a decrease in anthropogenic impact on the environment.