| 凤眼莲对铜绿微囊藻生长及藻毒素与营养盐释放的影响 |
| 摘要点击 2673 全文点击 1331 投稿时间：2013-06-03 修订日期：2013-09-01 |
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| 中文关键词 凤眼莲 铜绿微囊藻 藻毒素生产 藻毒素释放 藻毒素积累 |
| 英文关键词 Eichhornia crassipes Microcystis aeruginosa microcystins production microcystins release microcystins accumulation |
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| 中文摘要 |
| 针对目前我国凤眼莲治理富营养化水体技术的规模化应用现状，考虑到大面积控养的凤眼莲与暴发的水华蓝藻（尤其是产毒铜绿微囊藻）会在湖湾区短期内密集共存的情况，开展了凤眼莲对产毒铜绿微囊藻生长、生理特性、藻毒素生产与释放影响的研究，另外，也考察了短期共存下藻类营养盐释放与凤眼莲对藻毒素积累的情况. 半连续共培养实验结果表明，凤眼莲能够有效抑制铜绿微囊藻的生长，促进藻细胞的衰亡. 虽然凤眼莲未对铜绿微囊藻光合系统Ⅱ的电子传递产生影响，但减少了其光合系统中的藻蓝蛋白（PC）含量和藻蓝蛋白/别藻蓝蛋白（PC/APC）水平，10%和20%水体交换率处理的PC/APC水平第8 d时分别降至相应空白对照的54.93%±7.07%和55.81%±1.97%. 凤眼莲对铜绿微囊藻形成了一定的氧化伤害，最终促进其抗氧化系统中超氧化物歧化酶比活显著下降，丙二醛含量显著提高，10%和20%水体交换率处理的丙二醛含量第8d时分别升至相应空白对照的2.95倍±0.074倍和2.22倍±0.086倍. 凤眼莲通过促进蓝藻的衰亡和分解，加速了营养盐的释放. 12 d内，可溶性总氮浓度回升到初始水平，而水体可溶性总磷的释放速度比氮营养盐更快. 另一方面，凤眼莲并没有促进铜绿微囊藻毒素的生产，也没有使水体藻毒素含量显著提高. 相反，和自然衰减不同，短期内显著促进了水体藻毒素的降解，第12 d时10%和20%水体交换率处理的水体藻毒素分别下降至12.07 μg·L-1±0.63 μg·L-1和11.36 μg·L-1±0.04 μg·L-1. 而凤眼莲整株的藻毒素短期积累量（FW）仅为5.95 ng·g-1±0.76 ng·g-1. 增加水体交换率能够在一定程度上减缓凤眼莲对铜绿微囊藻的伤害，减缓营养盐的释放速度，但对水体藻毒素消减的影响不显著. |
| 英文摘要 |
| Due to the large-scale application of Eichhornia crassipes (Mart.) Solms on the bioremediation of eutrophic lake in China, the influence of growth, physiological characteristics, microcystins production and release of M. aeruginosa by E. crassipes was investigated. Meanwhile, the release risk of nutrients from M. aeruginosa and the accumulation risk of microcystins in E. crassipe were explored through semi-continuous co-existence experiments. Our results indicated that M. aeruginosa was promoted by E. crassipes to undergo the cell death. Under the stress of E. crassipes, direct damage of phycocyanin and phycocyanin/allophycocyanin ratio in M. aeruginosa occurred, while the photosystem Ⅱ-Hill reaction in M. aeruginosa was not interrupted. The PC/APC levels in the treatment of 10% and 20% water exchange rate were respectively decreased to 54.93%±7.07% and 55.81%±1.97% of the level in their relative controls after 8 days. Then, the final significant decrease of specific superoxide dismutase activity and the striking elevation of malondialdehyde content in M. aeruginosa could be the results of oxidative damage by E. crassipes. Algal malondialdehyde content in the treatment of 10% and 20% water exchange rate were respectively 2.95±0.074 and 2.22±0.086 times of the level in their relative controls on day 8. The release of nutrients from M. aeruginosa was accelerated because the decay and lysis of algal cells were promoted by E. crassipes. After 12-day co-existence experiments, the concentration of total dissolved nitrogen in water was brought back to the initial level and the release of total dissolved phosphorus was faster than nitrogen nutrients under the stress of E. crassipes. In addition, the microcystins production in M. aeruginosa was not stimulated and the extracellular microcystins were significantly eliminated by the influence of E. crassipes. The extracellular microcystins contents in the treatment of 10% and 20% water exchange rate were respectively decreased to 12.07 μg·L-1±0.63 μg·L-1 and 11.36 μg·L-1±0.04 μg·L-1 after 12 days.But the microcystins level in the whole plants of E. crassipes co-cultured with M. aeruginosa for 12 days was only about 5.95 ng·g-1±0.76 ng·g-1 FW. The increase of water exchange rate could reduce the damage of M. aeruginosa by E. crassipes,but had no significant effect on the microcystins elimination. |
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