| The effects of different temperatures, light intensities and mass concentrations of nitrogen on the growth and lipid synthesis of Tropidoneis maxima were studied. The results showed that the suitable temperature for the growth of Tropidoneis maxima was 20-30℃ and the optimal temperature was 25℃; lower temperature could promote the accumulation of EPA and DHA;when the temperature was 10℃, the contents of DHA and EPA achieved (3.02±0.64)% and (27.98±0.97)% respectively; the proper light intensity for the growth of Tropidoneis maxima was 32-48 μmol/(m2·s), however, the total lipid content was the highest when the light intensity was 80 μmol/(m2·s), reaching (34.66±0.86)%; lower light intensity was benefit for the algae to synthesize polyunsaturated fatty acids(PUFA), while higher light intensity helped the algae to increase EPA content; different mass concentrations of nitrogen had great effects on the growth and total lipid content (P<0.05), the appropriate mass concentration of nitrogen for the growth of Tropidoneis maxima was 20-30 mg/L and 25 mg/L was the best, but nitrogen deficiency could increase the total lipid content;higher mass concentration of nitrogen promoted the synthesis of EPA and PUFA, and the contents of EPA and PUFA increased significantly with the increase of the mass concentration of nitrogen; when the mass concentration of nitrogen was 25 mg/L, the contents of EPA and PUFA were the highest, reaching (24.67±0.44)% and (40.55±0.58)% respectively. |
