Growth Performance and Biochemical Composition of Tetradesmus obliquus in Media with Different Phosphorus Concentrations

In this study, the effects of phosphorus on culture growth and biochemical composition of Tetradesmus obliquus were investigated. T. obliquus was cultivated in medium with different P concentrations. Cell number, optical density and dry weight values were measured every other day and total protein and lipid content, amino acid and fatty acids profiles were detected. The highest cell number (2905x104), optical density (1.07) and dry weight (0.04 mgL-1) were observed in 75% P+ medium. 50% P- medium has the highest (47.7% of dry weight) protein amount and the maximum of total lipid content (17.08% of dry weight) was determined in 75% P- medium. 75% P+ medium has the highest total amino acid value (64.37 mgg-1 dry weight) and 75% P- medium has the lowest (55.22 mgg-1dry weight). The highest saturated fatty acids (23.57%) and mono-unsaturated fatty acids (19.97%) were observed in 50% P- medium. The second highest percentages of polyunsaturated fatty acids values were in the 75% P- medium (48.63 %). These results show that phosphorus limitation increases the total protein, lipid and fatty acid methyl esters amounts and restricts the cell division and anabolic reaction. An excess in phosphorus has an enhancing effect on amino acid synthesis.