Elevated temperature mitigates the prolonged effect of high nitrogen on Microcystis aeruginosa removal through mixotrophic Ochromonas gloeopara grazing
Elevated temperature mitigates the prolonged effect of high nitrogen on Microcystis aeruginosa removal through mixotrophic Ochromonas gloeopara grazing
复制标题
升高温度减轻了高氮对混合营养型 Ochromonas gloeopara 放牧去除铜绿微囊藻的长期影响
DOI：
10.1016/j.scitotenv.2022.153267
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发表时间：
2022
影响因子：
9.8
通讯作者：
Huang Yuan
中科院分区：
文献类型：
--
作者：
Wei Junjun;Li Xianxian;Xu Xiaoqing;Xu Wenjie;Chen Yitong;Zhang Lu;Yang Zhou;Huang Yuan
由于全球变暖和富营养化，蓝藻水华正日益威胁着水生生态系统的功能。像原生动物这样的消费者对蓝藻进行自上而下的控制，由于其有效性和环境友好性，显示出巨大的潜力。为了揭示营养有效性和温度升高对原生动物放牧去除蓝藻的影响，我们在25℃和30℃的环境相关氮素水平(L−1)下分别培养了有毒的绿微囊藻和混合营养的绿色单胞菌。Fm的增长。随着氮素浓度和温度的升高，铜绿假单胞菌的产量显著增加，部分得益于光合作用的促进。相比之下，氮的有效性既不影响混合营养藻光自养生长，也不影响对微囊藻的摄食。Gloeopara，但高温导致混养藻类更加异养，表现为光合作用受到抑制，取食活性增强。相应地，他们。铜绿假单胞菌通过O。在共培养条件下，随着氮素含量的增加，球化延缓，而温度升高则急剧加速。根据高斯模型拟合，随着施氮量的增加，去除微囊藻的理论时间从7.5天左右延长到10天左右，但在30℃时，各处理组的理论去除时间都缩短到4.6天以下。微囊藻水华的发生强度与营养条件和温度呈显著正相关，为野外放牧去除微囊藻的实际应用提供了参考。
Cyanobacterial blooms are increasingly threatening the aquatic ecosystem functioning as a result of the global warming and eutrophication. The “top-down” control of cyanobacteria from consumers like the protozoans shows great potential because of the effectiveness and environment-friendliness. To reveal how the nutrition availability and elevated temperature affect the cyanobacteria removal through protozoans grazing, we grew the toxicMicrocystisaeruginosaand the mixotrophicOchromonas gloeoparain monocultures and cocultures at environmentally relevant nitrogen levels (0.5–8.0 mg L−1) under 25 °C and 30 °C, respectively. The growth ofM. aeruginosain monocultures was significantly enhanced as nitrogen concentration and temperature rose, partially benefitting from the promoted photosynthesis. By contrast, nitrogen availability affected neither the photoautotrophic growth nor the feeding onMicrocystisof the mixotrophicO. gloeopara, but high temperature induced the mixotroph to be more heterotrophic as evidenced by the suppressed photosynthesis but strengthened feeding activity. Accordingly, theM. aeruginosaremoval throughO. gloeoparagrazing in cocultures was delayed with increasing nitrogen, which, however, was sharply accelerated by elevated temperature. Based on the Gaussian models fitting, the theoretical time that theMicrocystiswas removed at 25 °C was prolonged from about 7.5 days to 10 days with increased nitrogen, but it was reduced to less than 4.6 days in all groups at 30 °C. While the intensity ofMicrocystis blooms is strongly positively correlated to the nutrition availability and temperature, the present study provided references for the practical application ofMicrocystisremoval through grazing outdoors.