Total lipid accumulation and fatty acid profiles of microalga Spirulina under different nitrogen and phosphorus concentrations
Nutrient limitation in terms of nitrogen and phosphorus increased lipid accumulation under depleted growth in Spirulina strains. Nitrogen limitation was found more effective than phosphorus in accumulating lipid. The fatty acid profile was variable: palmitic (48%), linolenic (21%) and linoleic acids (15%) were the most prevalent types. It was interesting that nitrogen limitation was more effective in increasing total lipid content, whereas phosphorus limitation had more effect on the fatty acid profile. Fatty acid ratios were different under the two conditions of nutrient limitation, with γ -linolenic acid being accumulated in higher quantities under nitrogen than phosphorus limitation.