Electrochemical oxidation has been used to inflict injuries to cyanobacteria, halt their proliferation as for microcystin degradation in in vitro conditions. The electrochemical treatment resulted in abolishment of cell buoyancy regulation, cell proliferation arrest and eventually in cell death. The effectiveness of microcystin degradation was established using HPLC/PDA analysis while the biological activity of the products was estimated using a colorimetric protein phosphatase 1 (PP1) inhibition assay. The results indicate a potential for application of electro-oxidation methods in the control of bloom events by taking advantage of specific intrinsic ecological characteristics of bloom forming cyanobacteria.
COBISS.SI-ID: 3880271
Chlorophyll and phycocyanin fluorescence sensors were used simultaneously to detect stress caused by electrochemical oxidation by an electrolytic cell equipped with boron doped diamond electrodes on a laboratory culture of cyanobacteria Microcystis aeruginosa PCC 7806. The inflicted injuries were reflected in a clear transient increase in the phycocyanin fluorescence signal and less pronounced increase in the chlorophyll fluorescence signal 24 hours after the treatment. This result demonstrates the viability of the combined application of two sensors as an effective tool for in-vivo detection of induced stress, providing real-time information. The electrochemical treatment also resulted in cell proliferation arrest and a decrease in the concentration of free microcystins. Described combination of electrochemical treatment and chorophyll and phycocyanin fluorescence measurements shows promising results for the efficient in-lake treatment of cyanobacterial blooms.
Submergible sensors based on in vivo measurements of photosynthetic pigments fluorescence enable real-time phytoplankton monitoring with high spatial and temporal resolution. A combination of chlorophyll a (CHL) and phycocyanin (PC) fluorescence sensors was used for phytoplankton quantification and differentiation. Fluorescence signal of five phytoplankton representatives was first investigated in laboratory conditions. Comparison with standard methods for phytoplankton quantification (cell counts, amount of extracted pigments, biovolume) showed the highest uniformity among different species when fluorescence signal was correlated to the cell concentrations expressed as biovolume, which considers the difference in size of the individual cells. The high correlation of CHL and PC fluorescence signals with biovolume was confirmed during the two-year monitoring in a natural pond environment.