The effect of different nitrogen sources on the growth, lipit and protein amount of Scenedesmus acutus (Meyen)

The effect of different nitrogen sources on the growth, lipit and protein amount of Scenedesmus acutus (Meyen) In the present study, the effects of different nitrogen sources and concentrations on S. acutus, protein and lipid content were investigated. Jaworski's medium was used as control group. In the study, as all nitrogen sources were removed from Jaworski's media, new media with different nitrogen sources were prepared by adding KNO3, NaNO3, NH4NO3, CaNO3 and (NH4) 2SO4 at concentrations of 10.10, 20.20 and 40.40 g / l, respectively and the samples in cultures were examined throughout ten days. It was observed that different nitrogen sources and concentrations made significant changes in cell growth, protein and lipid content of S. acutus. Regarding all nitrogen sources, it was found that lipid content was higher in the cultures with low nitrogen concentration while cell growth and protein content was affected negatively. Plus, it was recorded that the cultures with high nitrogen concentration led to an increase in cell growth and amount of protein but decrease in amount of lipid. The OD value in all the cultures was displayed to increase until the sixth day of the experiment while the OD values decreased until the tenth day after the sixth day. The highest OD values were found to be 0.348, 0.344 in culture media prepared with 40.40 g / l KNO3 and 40.40 g / l CaNO3, respectively. The amount of protein was recorded to reach the maximum level in the sixth day following the inoculation in all cultures but a decrease was determined in the samples after the sixth day of the experiment. Highest protein contents were found as 255.65 µg/ml and 255.40 .4 µg/ml in cultures supplied with 40.40 g / l KNO3 and 40.40 g / l NH4NO3 respectively. The increase in the level of lipid was observed to continue until the sixth day following the inoculation in all cultures, but there was a decrease in the level of lipid in all cultures after the sixth day of the experiment. Highest lipid contents were found as %125,6 g/l, %120,3 g/l, %104,02 g/l in the cultures supplied with 10.10 g/l KNO3, 10.10 g/l NaNO3 ve 10.10 g/l NH4NO3 respectively. It can be concluded that cell growth, protein and lipid content, reaching the maximum level in culture media when KNO3 and NH4NO3 are used as nitrogen sources, were considerable findings of the study. Key words: Scenedesmus acutus, Nitrogen, Growth, Protein, Lipid, Biofuel.