Abstract
The effect of Pb (CH3COO)2 solutions with Pb2+ concentrations equal to 0.02, 0.1, 0.2 and 0.4 mM to strain of cyanobacteria (CB) Leptolyngbya sp. SK was studied. The duration of exposure of the culture with solutions was 21 days. During the experiment, measured the loss of lead ions in the solution; the increase in the biomass of CB was assessed as an indicator of culture adaptation; determined the content of photosynthetic pigments as indicators of maintaining the viability of the culture. The content of lead ions decreased in all variants, the maximum decrease was 96.2% – in the medium with a Pb2+concentration of 0.4 mM. An increase in the biomass of CB was observed in the presence of Pb2+ of all concentrations, the maximum increase in a solution with a Pb2+ concentration of 0.1 mM was up to 7.5 times. There was a decrease in the content of chlorophyll a in the biomass of CB, in comparison with the control, by 67.0–94.2% with an increase in the concentration of Pb2+ in the solution. Under the influence of solutions with Pb2+ concentrations of 0.02, 0.1, and 0.4 mM, the content of carotenoids in the biomass of cyanobacteria decreased by 48%, 75% and 92%, respectively; the concentration of Pb2+0.2 mM caused an increase in the content of carotenoids by 1% with the control. The inhibitory effect of all investigated concentrations of Pb2+ was noted on the complex of phycobilin pigments. The accumulation of lead ions from solutions with Pb2+ concentrations up to 0.4 mM, an increase in CB biomass in the presence of 0.1 mM Pb2+ and an increase in the synthesis of carotenoids at 0.2 mM Pb2+ may indicate adaptation of the studied culture to lead acetate.