Abstract
Algalogically pure cultures were isolated from different aquatic ecosystems and identified as representatives of green algae, euglena algae, and cyanobacteria. Isolated cultures and collection strains of microalgae were screened for productivity. Induced mutagenesis (exposure to UV radiation, 254 nm, 40 Erg/mm 2 ) and selection yielded a mutant strain C-2m2 of Chlorella pyrenoidosa notable for a high activity of lipid biosynthesis and accumulation. Optimization of its culture conditions was conducted. It was found that the active lipid accumulation by the cells of C. pyrenoidosa strain C-2m2 occurred when nitrogen concentration in the medium was tenfold reduced (to the level of 0.004 g/L) at an illuminance of 4 klx.