GROWTH AND BIOCHEMICAL-COMPOSITION WITH EMPHASIS ON THE FATTY-ACIDS OF TETRASELMIS SP

The influence of temperature (15-32-degrees-C) and the ratio of nitrogen to phosphorus (N/P) in the culture medium (0.5-80) on the growth kinetics and protein, chlorophyll, lipid and fatty acid content of the marine microalga Tetraselmis sp. have been studied. Below an N/P of 20, growth was determined by N limitation and above 20 by P limitation. Protein increased with a rise in N content at any test temperature. The chlorophyll content increased with temperature, with maximum values at 25-degrees-C. The lipid content decreased with increasing N/P ratio above 20-degrees-C. The polyunsaturated fatty acid content tends to be inversely proportional to the growth rate within the N/P range 20-80. The quotient of the n3 and n6 polyunsaturated-fatty-acid fractions, an indicator of the nutritive value of microalgae, was found to be within the range 2-3. These values were obtained either between 25 and 28-degrees-C independent of the N/P ratio used or at 20-degrees-C for N/P ratios higher than 40.0.