Segin T. Adaptation of green photosynthetic sulfur bacteria Chlorobium limicola IMV K-8 to the influence of copper (II) ions

The dissertation presents the results of the study of the response of green photosynthetic bacteria Chlorobium limicola IMV K-8 to the action of copper ions and to find out the possibility of application of these bacteria in co-culture for electric current generation. CuSO4 in concentrations 0.05–0.50 mM that cause decrease in biomass accumulation by 10–70 % were chosen for studying the mechanisms of damaging influence and adaptive reactions of C. limicola IMV K-8. Under the influence of studied concentrations of salt, copper ions were accumulated in bacterial cells. The processes of lipid peroxidation were intensified due to the effect of copper ions on the cells of C. limicola IMV K-8. The accumulation of lipoperoxidation products, such as lipid hydroperoxides, conjugated dienes and thiobarbituric acid reactive substances was observed in bacterial cells. The content of carbonyl groups in proteins of C. limicola IMV K-8 decreased by 10–78 % under the influence of CuSO4 with the increase of metal salts concentration in the incubation medium and the duration of cultivation in comparison with control. It was found that under the influence of CuSO4 the content of bacteriochlorophylls a, c, d, chlorobactin and lycopene decreased by 40–99 % in comparison with the control. The response of C. limicola IMV K-8 cells to the influence of copper ions is caused by the activity of superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase. It was found that synthesis of reduced glutathione in C. limicola IMV K-8 cells under the influence of CuSO4 increased by 2.5–3.0 times in comparison with control. It was found that green photosynthetic bacteria C. limicola IMV K-8 synthesize glycogen during growth in the wastewater of the distillery plant. It was found that during the phototrophic growth in the wastewater of the distillery, the glycogen content was by 2.5 times higher, than the glycogen content in the cells, cultivated in the medium for green photosynthetic bacteria GSB. Carboxylic acids formed as a result of metabolism of glycogen C. limicola IMV K-8, in particular acetate, can be a substrate for electric current generation by exoelectrogenic bacteria. The combination of phototrophic microorganisms C. limicola IMV K-8 with exoelectrogens Desulfuromonas acetoxidans IMV B-7384 is a promising approach for development of technologies for generation of electricity.