Kalinovskaya A. Peculiarities of functioning of freshwater algae under the influence of various light quality and intensity.

The thesis focuses on the research of peculiarities of functional alterations in the cells of freshwater algae under conditions of changes in parameters of the light field -spectral composition of light and its intensity. The paper demonstrates distinctions in return reactions of algal pigment system of different systematic groups (blue-green, green and diatoms) on exposure to UV-radiation, and the obtained data certify that examined representatives of Cyanophyta, as compared to Chlorophyta and Bacillariophyta, show greater resilience to UV-light exposure. In the experiments with cultures it has been established that examined blue-green algae compared with green algae are more adapted to low intensity of visible light, they grow better under the influence of red and blue light and under a longer photoperiod. On the biochemical level it was determined that formation of adaptive protection systems of different systematic groups of algae exposed to light of various spectral compositions takes place by functional alterations of key components of lipid, nitrogenous and energy metabolism. Detected peculiarities of algal metabolism under conditions of alteration of light quality and intensity are of high importance for decoding mechanisms of formation and functioning of freshwater algal communities.