| 摘要: |
| 栅通过油脂分析、光合放氧、叶绿素荧光等手段, 研究了缺氮处理对栅藻(Scenedesmus dimorphus)油脂含量、油脂组分以及光合作用影响。结果显示, 总脂含量由22.4%±0.6% 提高到36.3%±0.7%, 其中甘油三酯含量由4.6%±1.2% 提高到68.3%±2.5% 而磷脂含量由92.8%±1.6% 降低到26.8%±2.0%。缺氮处理1 d 后, 叶绿素含量明显下降, 呼吸速率明显升高。缺氮处理初始阶段, 栅藻光系统Ⅱ最大光能转化效率(Fv/Fm)和非光化学猝灭系数(NPQ)维持稳定, 4 d 后Fv/Fm显著降低而NPQ 显著升高。上述变化可能是光能过剩引起的防御反应, 也可能是自身代谢模式发生转变的结果而与光能耗散无关。 |
| 关键词: 栅藻(Scenedesmus dimorphus) 缺氮 油脂积累 光合作用 |
| DOI： |
| 分类号: |
| 基金项目:科技部国家科技支撑计划(2011BAD14B01); 中国科学院太阳能行动计划(KGCX2-EW-309) |
|
| The effects of nitrogen starvation on lipid accumulation and photosynthesis of Scenedesmus dimorphus |
|
|
| Abstract: |
| The microalga Scenedesmus dimorphus could be potentially used as feedstock for biodiesel production. However, the changes in photosynthesis during lipid accumulation are still unclear for this organism. Herein, the effects of nitrogen starvation on the lipid content, lipid component and photosynthesis of Scenedesmus dimorphus were studied using lipid analyzing, photosynthetic oxygen evolution and chlorophyll fluorescence methods. The results showed that the total lipid content was increased from (22.4 ± 0.6)% to (36.3 ± 0.7)% during the nitrogen starvation, companied by the increase of triacylglycerol from (4.6 ± 1.2)% to (68.3 ± 2.5)% and decrease of phospholipid from (92.8 ± 1.6)% to (26.8 ± 2.0)%. The chlorophyll content was decreased steeply while the respiration rate was increased after 1 day nitrogen starvation treatment. The maximum photo-chemical efficiency of photosystem Ⅱ(Fv/Fm) and non-photochemical quenching co-efficiency (NPQ) were kept in a stable level during the first several days of nitrogen starvation, and then Fv/Fm decreased while NPQ increased significantly after 4 days treatment. All these changes in photosynthesis might be due to 1) the defensive reaction against the excess light energy, or 2) non-related with the energy dissipation but due to the shift from vegetative growth to secondary metabolism. |
| Key words: Scenedesmus dimorphus nitrogen starvation lipid accumulation photosynthesis |
