Variations in lipid profile of the marine microalga Nannochloropsis salina in four different culture media

The present work envisages close monitoring of variations in lipid content and fatty acid profile of the marine microalga Nannochloropsis salina, by growing it in 4 different culture media. Pure cultures of microalga were collected from the marine hatchery complex of the ICAR-Central Marine Fisheries Research Institute, Kochi and cultured in four different media viz, f/2 medium (Guillard,1975), Miquel's medium (Miquel,1892), Walne's medium (Walne, 1974) and Chu#10 medium (Chu, et al., 1942). Standard algal culture conditions viz, salinity 33 ppt, pH 8.0, culture room temperature of 25 degrees C, light intensity of 1500 lux with a photoperiod of 12 h and Light:Dark cycle of 12 h were maintained. Lipids extracted were subjected to gas chromatography to ascertain their fatty acid profile. Both Miquel's and f/2 media produced the maximum amount of lipid content (40.2 and 40% respectively). Total saturated fatty acids ranged from 39.17% (Miquel's medium) to 84.45% (Chu #10). For monounsaturated fatty acids, the highest value was obtained for Miquel's medium (42.79%) and minimum for Chu#10 (10.55%). Polyunsaturated fatty acids accounted for over 23.5% of the total fatty acids in Walne's medium followed by Miquel's (18.04%), f/2 (12.76%) and Chu#10 (5%) media. One way analysis of variance of the data brought to light that the medium composition can influence the fatty acid pattern of microalgae significantly.