Effect of nitrogen concentrations on microalgae growth and biochemical composition

In this study, the changes in biomass increase and intracellular biochemical composition caused by different concentrations of nitrogen in a nutrient medium using the Monoraphidium contortum species were examined. Monoraphidium contortum species was obtained from Kırşehir Ahi Evran University Cultural Collection. 5 different nitrogen concentration modifications were applied to the BG-11 nutrient medium as 0 % N, 25 % N, 50 % N, 75 % N and 100 % N. 250 mL of the grown cultures were taken and planted in 5 different modified BG-11 nutrient media. Cultures were grown at 23±2°C in a 16:8 light/dark photoperiod (50 μmol m-2s-1). In examining biomass development, cell densities, dry weight, chlorophyll-a, carotenoids and fatty acids were determined. While the maximum percentage lipid content of Monoraphidium contortum was obtained from the culture grown in (50 % N) medium of 32.11%, the lowest lipid amount was determined as 14.56 % in (100 % N) medium. Key Words: Monoraphidium contortum, Nitrogen limitation, Biomass, Lipid