Chlorophytes prolong mixotrophic Ochromonas eliminating Microcystis: Temperature-dependent effect.
Chlorophytes prolong mixotrophic Ochromonas eliminating Microcystis: Temperature-dependent effect.
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DOI：
10.1016/j.scitotenv.2018.05.196
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Lu Zhang;L. Gu;Xinying Hou;Qingdan Kong;Ke Chen;Xuexia Zhu;Yuan Huang;Yafen Chen;Zhou Yang-Zho
中科院分区：
文献类型：
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作者：
Lu Zhang;L. Gu;Xinying Hou;Qingdan Kong;Ke Chen;Xuexia Zhu;Yuan Huang;Yafen Chen;Zhou Yang-Zho
蓝藻水华是由水体富营养化和气候变暖引起的，对水体生态系统造成了严重的负面影响。一些原生动物能以有毒蓝藻为食，并能高效降解藻毒素，这为控制有害藻类提供了一条很有前途的途径。然而，在野外，许多不同种类的藻类与微囊藻共存，可能会影响原生动物对微囊藻的清除。因此，本研究探讨了不同温度下，绿藻（一种对浮游动物有益的藻类，也是蓝藻的常见竞争者）对鞭毛藻-实验结果表明，在添加绿藻的条件下，虽然藻毒素的去除时间延长，且具有温度依赖性，但藻毒素的去除率和总藻毒素的去除率均有所提高。此外，在放牧处理中，随着微囊藻的减少，绿藻的数量逐渐增加，而在不含发色单胞菌的混合藻培养中，微囊藻占优势。研究结果表明，虽然绿藻延长了混合营养型嗜铬单胞菌消灭微囊藻的时间，但在初级生产者中，鞭毛虫食草型微囊藻占优势，这对改善水质、降低水生态系统风险具有重要意义。
Cyanobacterial blooms, caused by eutrophication and climate warming, exert severely negative effects on aquatic ecosystem. Some species of protozoans can graze on toxic cyanobacteria and degrade microcystins highly efficiently, which shows a promising way to control the harmful algae. However, in the field, many different species of algae coexist withMicrocystisand may affect protozoans eliminatingMicrocystis. Therefore, in this study, we assessed the impacts of chlorophytes, a type of beneficial algae for zooplankton and common competitors of cyanobacteria, on flagellateOchromonaseliminating toxin-producingMicrocystisat different temperatures. Our results showed thatOchromonasstill eliminatedMicrocystispopulation and degraded the total microcystins with the addition of chlorophytes, although the time of eliminatingMicrocystiswas prolonged and temperature-dependent. Additionally, in the grazing treatments, chlorophytes populations gradually increased with the depletion ofMicrocystis, whereasMicrocystisdominated in the mixed algal cultures withoutOchromonas. The findings indicated that although chlorophytes prolong mixotrophicOchromonaseliminatingMicrocystis, the flagellate grazingMicrocystishelps chlorophytes dominating in the primary producers, which is significant in improving water quality and reducing aquatic ecosystem risks.