The experience of application of microbiological indicators in monitoring procedures of aquatic ecosystems in the Middle Ob basin

The results of microbiological monitoring of the rivers with the various nature and intensity of anthropogenic load in the Middle Ob basin carried out from 2002 to 2019 is presented. The programme of monitoring included following parameters: the number of bacteria of 5 ecologicaltrophic groups, gram-staining and morphology of isolated bacteria study, testing of bacterial resistance to antibiotics and phenols. Also coefficients of mineralization and Water quality indexes were calculated. On the base of calculated values, the self-purification potential of the rivers was estimated. Studied rivers were categorized into 5 classes of water quality. In the most rivers on unpolluted and urban area G+ and coccus forms of bacteria were predominant in the microbial community. In the rivers within oilfields the proportion of G- and rod-shaped bacteria was increased considerably. Seasonal and spatial distribution of resistant bacteria over the rivers allows to apply them as markers of the nature and intensity of the anthropogenic load.