It has been shown that hydrogen peroxide, singlet oxygen and shungite affect the development of the population of cyanobacteria Anabaena variabilis and Synechocystis sp. PCC 6803 in different directions. The growth of cyanobacteria culture slows down in the presence of photosensitizer and hydrogen peroxide. In this case, the number of cells depends on the amount of shungite in the environment. Cyanobacteria Anabaena variabilis and Synechocystis sp. PCC 6803 grow better in the presence of 10 g/L shungite, but growth is suppressed at 100 g/L. Shungite at 10 g/L protectes cultures from the toxic effects of Bengal pink and hydrogen peroxide, which was determined by the level of photosynthesis efficiency and cell amounts. The growth of Anabaena variabilis (in terms of optical density at 680 nm) has been found to slow down in the presence of only hydrogen peroxide relative to the control. The growth of Anabaena variabilis in the presence of shungite and hydrogen peroxide is restored to the level of control samples. The number of cyanobacterium Synechocystis sp. PCC 6803 cells slows down significantly in the presence of singlet oxygen. Being combined with singlet oxygen, shungite partially inactivates the action of Bengal pink. At the end of the experiment, the growth of the culture is restored to 60% compared to the control. A similar relationship is observed when evaluating the effectiveness of photosynthesis of cyanobacteria Anabaena variabilis and Synechocystis sp. PCC 6803. Thus, singlet oxygen is more toxic than hydrogen peroxide. This may be due to different mechanisms of action of hydrogen peroxide and singlet oxygen on cyanobacteria growth. Depending on the content in the water, shungite can stimulate or inhibit the growth of cyanobacteria cells, inactivate the action of a toxicant.
Histidine kinases play important roles in the perception and signal transduction of hydrogen peroxide in the cyanobacterium, Synechocystis sp. PCC 6803
