Structural and Functional Changes in Bacterial Population of the Lake as a Response to Hydrotechnical Construction (by Example of Opechen Nyzhne Lake, Kyiv, Ukraine)

The paper deals with structural and functional indicators of bacterioplankton and bacteriobenthos of Opechen Nizhny Lake before (2016-2018) and after (2019-2021) its hydrotechnical reconstruction and improvement of the surrounding areas are presented. The analysis of seasonal dynamics of bacterioplankton, bacteriobenthos, eutrophic and oligotrophic bacteria, bacteria with a damaged cytoplasmic membrane (dead cells) and bacteria with active electron transport chain (alive cells) number in water and bottom sediments, intensity of destruction and bacterial decomposition of organic matter in water was analyzed. Significant development of sanitary-indicative microorganisms in the lake water was revealed. The comparative analysis of the quantitative development and functioning of the bacterial population of the lake over two investigated periods was carried out. The results obtained can be used to reveal the mechanisms of formation and functioning of pollution-resistant microbial communities in anthropogenically polluted and reconstructed water bodies, as well as their role in the self-purification processes.