氯化钠处理对原壳小球藻生长及油脂积累的影响

采用Basal培养基,通过光学显微镜、电子显微镜、激光共聚焦显微镜以及尼罗红染色定量等方法研究了不同浓度氯化钠(0、150、300、600 mmol/L)对小球藻属原壳小球藻的生长状态、脂滴分布、总脂含量的影响。结果表明,添加不同浓度的氯化钠对原壳小球藻的生长有明显的影响,随着氯化钠浓度的增加,小球藻的生长速度受到明显的抑制,600 mmol/L氯化钠处理时生长几乎完全被抑制。在显微镜下观察,可见氯化钠浓度的增加会导致小球藻聚集成团,这种现象在150 mmol/L和300 mmol/L氯化钠培养下比较明显;通过电子显微镜下观察,可以发现培养初期,随着氯化钠浓度的增加,小球藻细胞壁增厚,脂滴增多。通过尼罗红染色对脂含量进行定量,处理初期脂滴的合成量在600 mmol/L时最高,但到后期,随着藻生物量的增加,150 mmol/L和300 mmol/L处理下脂合成量逐渐升高,而对照小球藻脂合成量基本不变。稳定期后,从生物量(干重)和脂总量来看,300 mmol/L氯化钠培养处理的小球藻虽然生物量只有对照的73.55%,但是总脂含量却是对照的2.22倍,可见一定浓度的氯化钠处理一定时间可显著提高原壳小球藻的油脂含量。

Effect of sodium chloride on growth and lipid accumulation of Chlorella protothecoides CS-41

With basal medium, we studied the growth status, lipid droplet distribution, total lipid content of Chlorella protothecoides CS-41 treated with different concentrations of sodium chloride (0, 150, 300 and 600 mmol/L) by optical microscopy, electron microscopy, confocal laser focusing and Nile red staining. Results show that the addition of NaCl affected the growth of Chlorella protothecoides CS-41. With the increase of NaCl concentration, the growth rate of Chlorella was inhibited. Chlorella cell wall became thicker, and lipid droplets increased. At the early stage, the amount of lipid droplets in the 600 mmol/L NaCl culture was the highest, but at the late-log stage, the amount of lipid droplets increased with the increase of the biomass of culture in 150 and 300 mmol/L NaCl culture. At the stable stage, biomass (dry weight) in 300 mmol/L NaCl culture was 73.55% of that in the control, but the total lipid content was 2.22 times higher than that in the control. A certain concentration of sodium chloride treatment can significantly increase the lipid content of Chlorella protothecoides CS-41.