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Rychlost růstu dominantních rybničních sinic
SYSLOVÁ, Petra
The bachelor thesis deals with the determination of cyanobacterial growth from ponds. The results are used to determine the growth potential in connection with eutrophication, i.e. increasing the concentrations of nutrients in water. Cultured strains of Cyanobium gracile A1 and Synechocystis sp. PCC7509 were used in the experiment. To determine their growth, static cultivation was used in culture plates with different well volumes of Thermo Scientific NunclonTM Delta Surface 96 Well and Cellstar 48 Well Cell Culture Plate, which were evaluated as the most suitable from the first part of the experiment. Cyanobacteria were cultured in concentrations from 0.06 to 30 mg P mg/l in Z medium. To measure the growth, a spectrophotometer measuring fluorescence and absorbance was set up at OD750 nm wavelength. At this wavelength cyanobacteria have negligible absorption and therefore turbidity was used to measure biomass. Growth curves were created from individual measurements and are shown in the form of graphs. The results show that the highest concentration used, 30 mg P/l, caused growth inhibition. Cyanobacteria in an environment with a concentration of 0.06 mg P/l showed acceptable growth values. However, at a concentration of 0.46 mg P/l, which is twice the current concentration of P in ponds, cyanobacteria showed much higher growth values. And even at a concentration of 15 mg P/l, cyanobacteria reached the highest growth values. It can therefore be expected that if the concentration of P in the ponds rises to the values of 15 mg P/l, a rapid development of cyanobacteria will take place in the pond. At the end of the experiment, I was supposed to measure the growth rate in the lighting gradient, but due to the announcement of the closure of universities due to the COVID - 19 virus, I was not able to fulfil that.
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