| 加压对微囊藻的影响及其生态风险探讨 |
| Effects of Pressure on Microcystis Growth and Analysis of the Ecological Risk |
| 投稿时间：2020-05-08 修订日期：2020-12-02 |
| DOI：10.15928/j.1674-3075.2020.06.008 |
| 中文关键词:加压控藻 蓝藻水华 伪空胞 微囊藻 生态风险 |
| 英文关键词:algae control by high pressure cyanobacterial bloom gas vesicle Microcystis ecological risk |
| 基金项目:国家水体污染控制与治理重大科技专项(2017ZX07203-001)；云南省科技计划项目(2018BC002)；盐城市项目(YCCG1610-121) |
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| 中文摘要: |
| 为了探讨加压后微囊藻的生长变化及其对水质的影响，通过研究加压对微囊藻的伪空胞、细胞形态、群体粒径、光合活性、漂浮率的影响，缓解富营养化水体表面的蓝藻水华堆聚问题，探究加压后下沉蓝藻的去向及其可能导致的水质生态风险，实验比较了未加压和加压微囊藻在有光和无光条件下的生长差异。结果显示，在0.7 MPa、30 s加压条件下，水体表面漂浮的微囊藻群体在加压后迅速下沉，漂浮率由95%下降至1.99%；藻细胞内的伪空胞破裂，藻细胞变形萎缩，群体粒径变小，光合活性下降，但细胞膜未破损。未加压和加压后的藻样在有光与无光条件下培养的第3天，加压下沉的藻在光照条件下有17.91%重新上浮至水体表面，并且其光合活性逐渐恢复。透射电镜结果显示，上浮藻细胞内有伪空胞重新生成；反转录PCR结果表明，实验第3天，光照加压处理组伪空胞gvpA和gvpC基因表达较其他实验组显著上调，表明细胞进行了伪空胞合成过程。所有处理组水体中溶解性总氮（DTN）含量在前3 d无明显变化，但3 d之后均不断上升；且加压后水体中DTN含量无光条件比有光条件更高。研究表明，加压后下沉的微囊藻在无光条件下更易衰亡并释放有机物，导致水体DTN含量增加，应及时清除下沉蓝藻，避免水质恶化。 |
| 英文摘要: |
| Under a certain high pressure, the gas vesicles inside cyanobacteria collapse, and the cyanobacteria lose buoyancy and sink. Based on this principle, some novel technologies, such as a boat with pressure chambers and pressurized deep-well systems, have recently been developed to alleviate the problem of cyanobacterial accumulation on the surface of eutrophic waters. However, there is still a lack of research on the fate of the sunken cyanobacteria after pressure treatment and the potential ecological risk to water quality. In this study, we investigated the effect of pressure on the Microcystis growth and the change in water quality after treatment, focusing on the gas vesicle, cell morphology, colony size, photosynthetic activity and floating rate of Microcystis. Results show that under the condition of 0.7 MPa pressure for 30 s, the Microcystis colonies floating on the water surface rapidly sank, and the floating rate decreased from 95% to 1.99 %. The gas vesicles in algal cells collapsed, algal cells deformed and shrank, and colony size and photosynthetic activity decreased, but the cell membrane was still intact. On the third day after pressure treatment, 17.91% of the sinking Microcystis refloated to the water surface under light, and photosynthetic activity recovered gradually. Transmission electron microscopy showed that gas vesicles were regenerated. Moreover, the results of reverse transcription PCR showed that the expression of gvpA and gvpC genes in pressurized Microcystis under light was significantly up-regulated compared with other experimental groups, also indicating re-synthesis of gas vesicles. The content of dissolved organic nitrogen (DTN) in all treatment groups was constant for 3 days, but then increased continuously. The DTN content in the pressurized water was higher under dark condition than with light. In summary, controlling algae with pressure causes Microcystis on the water surface to sink rapidly but the algae, to some extent, will regain buoyancy within 3 days if light is available. Further, with light, the Microcystis that do not recover tend to decay more quickly, releasing organic matter and increasing the DTN content of water. Therefore, to improve water quality, the cyanobacteria that sink after pressurization must be removed before those that recover float back to the surface and those that do not release their nutrients. |
| 杨翠平,霍 岩,刘 津,张学治,李 林,宋立荣.2020.加压对微囊藻的影响及其生态风险探讨[J].水生态学杂志,41(6):65-73. |
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