不同氮源对骨条藻光合活性、生长和中性脂积累的影响

研究了硝酸钠、氯化铵和尿素作为单一氮源对骨条藻的光合活性、生长及中性脂积累的影响.结果表明:最适合骨条藻生长的氮源是氯化铵,其次是尿素,最后是硝酸钠,3种氮源的最适浓度均为4.4×10-4mol/L,光合活性的结果与藻的生长基本一致.3种氮源各浓度梯度的中性脂积累量最大值基本都出现在第7天(培养时间为8d),与藻的生长不是同步关系.最适合骨条藻中性脂积累的氮源是氯化铵,最适浓度为8.8×10-6mol/L,其最高油脂含量为31.07%.硝酸钠组的最高油脂含量为28.46%,略高于尿素组的最高油脂含量27.99%,但尿素组最适合中性脂积累的氮源浓度为1.8×10-5mol/L,低于硝酸钠组的最适氮源浓度1.8×10-4mol/L.在高接种量的条件下,骨条藻油脂总量的高低与百分含量的高低是基本一致的.

Effects of Different Nitrogen Sources on the Photosynthetic Activity,Growth and Neutral Lipid Accumulation of Skeletonema

The effects of sodium nitrate, ammonium chloride and urea as the nitrogen sources on the photosynthetic activity, growth and neutral lipid accumulation of Skeletonema were studied. The most suitable nitrogen for the growth of Skeletonema was ammonium, then urea and the last was nitrate. The optimum concentration of the three nitrogen sources for Skeletonema growth were all 4.4 × 10^-4 mol/L. The photosynthetic activities of Skeletonema were consistent with its growth rate. The highest accumulation of neutral lipid in the three nitrogen sources nearly all appeared on the 7th day, though the incubation period was 8 days. So the growth and neutral lipid accumulation of algae were not synchronous. The most suitable nitrogen for neutral lipid accumulation of Skeletonema was ammonium, when its optimum concentration was 8.8 × 10 ^-6 mol/L, and its highest lipid content was 31.07%. The highest lipid content of nitrate was 28.46%, slightly higher than the highest lipid content of urea, which was 27.99%. But the optimum nitrogen concentration of urea for neutral lipid accumulation of Skeletonema was 1.8 × 10 ^-5 mol/L, less than the total lipid content of Skeletonema was basically the same optimum concentration of nitrate, which was 1.8 × 10^-4 mol/L. The as its lipid percentage.