S.G. Vasilieva, I.M. Sedych, A.A. Lukyanov, I.O. Omarova, A.Kh. Tambiev

The recent publications mentioned in this article show that the lack of lithium in animal diet leads to poor lipid metabolism, reproductive problems and behavioral abnormalities. The low level of lithium in drinking water is correlated with higher level of mental diseases, violent crimes and other abnormalities. These evidences indicate that lithium may be an essential mineral in the human diet but it is not generally accepted currently. In our work we showed the possibility of obtaining enriched with lithium the biomass of cyanobacteria S. platensis and S. maxima which are the widespread objects of photobiotechnology. The optimal concentration of lithium in cultural medium was determined for both cultures (1.5 g/l), at this concentration the intracellular content of lithium is large and yield of biomass does not decreased considerably. At this concentration the accumulation of Li by S. platensis and S. maxima cells was 805±78 mkg/g and 853±103 mkg/g correspondingly. The analyses of lithium content and elemental composition of cells was fulfilled using the modern methods of atomic absorption (AAS) and atomic emission spectrometry with inductively coupled plasma (ICP). At concentration of lithium in cultural medium - 2.0 g/l the content of K in cells of S. platensis and S. maxima decreased correspondingly by 60 % and 40 % as compared with control. At the same lithium concentration the sodium content increased approximately three times, the content of Mn - by 80 %, the content of Fe - by 50 % as compared with control. At the concentration of lithium in cultural medium more than 2.0 g/l the cells of both cultures started to form dense bunch of trichomes and the morphology of cells changed greatly.