The growth of two robust algae strains Chlorella sp. and Scenedesmus sp. growing in Lithuanian lakes was investigated with the aim to obtain optimum conditions for biomass cultivation for biofuel production in the Lithuanian environment. Samples were taken from different nitrogen sources and of different concentrations, with addition of various concentrations of CO 2 and in the presence of salt. The best biomass productivity was achieved using urea as a nitrogen source or modified growing medium BG11 with decreased concentration of NaNO 3 . The positive impact on the growth of biomass was achieved by aeration with CO 2 (especially with concentration of 24%). Additional research into the removal of pollutants, such inorganic salts of nitrogen and phosphorus and organic materials from wastewater using microalgae has revealed good possibilities of using both algae strains in wastewater treatment plants. A content of oil in Chlorella sp. and Scenedesmus sp. has suggested their potential use as biodiesel feedstock.