| 초록 |
The high lipid content of microalgae is first required for biodiesel production and it can be increased by environmental stress including nutrient limitations. However, these methods also can result in a drop of cell growth. Thus, both of high lipid content and high cell density are important not to miss the high lipid productivity. In this study, the effects of nitrogen, phosphorous, sulfate and salinity limitations on Tetraselmis sp. were investigated first. The variations of N, P and SO42- did not affect the lipid content of Tetraselmis sp. whereas, when the salinity was lowered from 35 to 26, 17.5, 8.8, 3.5 psu, repectively, lipid content increased from 16 to maximum 31%. However, below 17.5 psu, the cell growth also has dropped. Consequently, gradual decrease of salinity was applied to get both of high cell density and lipid. When the salinity decreased gradationally from 35 to 28, 22, 18, 14 psu, high cell density (above 1.5 g/L) was maintained and lipid content also increased from 20 to 26% within 3 days, thereby, high lipid productivity can be achieved. |
