| 摘要: |
| 近年来，由于陆源污染的加重以及近海环境治理的推进，我国近海海域营养盐浓度发生明显变化，导致浮游植物生物量及群落结构发生改变。作为一种广泛分布且丰度较高的微微型蓝藻，聚球藻在我国近海生态系统中发挥着重要的角色，但其对不同硝酸盐浓度的响应尚待研究。本文分别从渤海和黄海采集聚球藻富集样本，在不同硝酸盐浓度下进行半连续培养，通过测定生长曲线、色素含量、光合生理参数以及碳氮含量，研究聚球藻对硝酸盐浓度的响应特征。当硝酸盐浓度为0.1、1.0、10.0 μmol L-1时，聚球藻培养体系可支持的生物量较小，光能转化效率较低；当硝酸盐浓度为100.0 μmol L-1时，聚球藻细胞生长得到促进，其培养体系可支持的生物量约提高5倍，同时培养体系整体的光能转化效率达到最高，但单位细胞的捕光能力受到抑制，氮和磷的转化率提高。研究表明海洋聚球藻能够适应不同的硝酸盐浓度维持生长，在较高的硝酸盐浓度下，聚球藻生物量显著提高，但释放至胞外的碳氮未出现相应的当量增加。研究结果为营养盐胁迫条件下浮游生态系统的响应提供了原核微藻方面的实验依据。 |
| 关键词: 海洋聚球藻 硝酸盐 生理响应 生物量 光合作用 |
| DOI： |
| 分类号:P735???? |
| 基金项目:中国科学院海洋大科学研究中心重点部署项目(COMS2020Q09)；国家自然科学基金(42176131) |
|
| Response characteristics of marine Synechococcus under different nitrate concentrations |
|
SHI Feng1, ZHOU Yu-ting2, LI Jia-lin2, GAO Hui-wang1, QIN Song2
|
|
1.College of Environmental Science and Engineering,Ocean University of China;2.Key Lab of Coastal Biology and Biological Resource Conservation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences
|
| Abstract: |
| With the increase of land-source pollution input and the promotion of offshore environmental restoration, nutrient levels have changed dramatically around China's continental shelf in recent years, resulting in the change of phytoplankton biomass and community structure. As a widely distributed and abundant microcyanobacteria, Synechococcus plays an important role in offshore ecosystems in China. However, its response to different nitrate concentrations remains unclear. In this research, the enriched samples of Synechococcus collected from the Bohai Sea and the Yellow Sea were used as experimental materials to conduct semi-continuous culture under different nitrate concentrations. The response characteristics of Synechococcus were demonstrated from the growth curve, pigment contents, photosynthetic physiological parameters, as well as carbon and nitrogen concentrations. The results showed that under the nitrate concentrations of 0.1, 1.0 and 10.0 μmol L-1, Synechococcus exhibited lower biomass and inefficient light energy conversion. Under the concentration of nitrate as 100.0 μmol L-1, the growth of Synechococcus was promoted, the biomass supported by the culture system increased by about 5 times, and the conversion efficiency of light energy reached the highest in the culture system. Meanwhile the light capture ability of unit cell was inhibited, and the consumption of nitrogen and phosphorus were increased. The research demonstrated that marine Synechococcus could maintain growth under different nitrate concentrations. For the higher nitrate concentration, its biomass increased significantly meanwhile there was no corresponding equivalent increase in carbon and nitrogen released into the culture medium. It provided experimental basis for prokaryotic microalgae to respond to phytoplankton ecosystem under nutrient stress. |
| Key words: Marine Synechococcus nitrate physiological responses biomass photosynthesis |