• 关键词：延缓期  指数增长期  稳定期  线性回归拟合  平均生长速率  胞内砷

• 基金项目：国家自然科学基金（No.41271477，41571470）

• 刘金鑫
• 1. 中国科学院地理科学与资源研究所, 北京 100101;2. 中国科学院陆地表层格局与模拟重点实验室, 北京 100101;3. 中国科学院大学, 北京 100049

• 谢邵文
• 1. 中国科学院地理科学与资源研究所, 北京 100101;2. 中国科学院陆地表层格局与模拟重点实验室, 北京 100101;3. 中国科学院大学, 北京 100049

• 杨芬
• 1. 中国科学院地理科学与资源研究所, 北京 100101;2. 中国科学院陆地表层格局与模拟重点实验室, 北京 100101;3. 中国科学院大学, 北京 100049

• 韦朝阳
• 中国科学院地理科学与资源研究所, 北京 100101

• 摘要：为了查明As（V）对不同生长期铜绿微囊藻生长和砷吸收的影响，分别在铜绿微囊藻的不同生长期，在低磷（0.02 mg·L^-1）、中磷（0.1 mg·L^-1）和高磷（0.5 mg·L^-1）水平，以及不同As（V）浓度下开展全因子室内模拟实验.结果表明，延缓期时，3个磷浓度下，As（V）添加均显著促进藻的生长，与对照组（CK）相比，平均生长速率（μ_2d，下同）增长21.49%~32.23%，但不同砷处理浓度之间无显著性差异；同一砷浓度处理时，磷浓度梯度变化对藻的生长也无显著性影响.指数增长期时，As（V）添加均显著抑制藻的生长，其中，低磷浓度条件下的抑制作用最强，与CK相比，μ_2d降低42.35%~106.30%，且随砷浓度升高呈线性下降，而中磷和高磷浓度下砷处理浓度之间无显著性差异.稳定期时，砷处理对藻的生长影响表现为逐渐升高的抑制作用（负生长速率值），其中，中磷浓度条件下抑制效应最高，与CK相比，μ_2d降低1387%~3181%，高磷浓度条件下抑制效应最低，μ_2d降低15.53%~378.00%.指数增长期和稳定期胞内砷含量结果表明，低磷浓度下不同生长期As（V）添加均显著促进藻细胞对砷的吸收，胞内砷含量大致随砷处理浓度增加而线性增长，而中磷和高磷浓度时藻细胞吸收砷的效应显著减弱，在指数增长期时则基本无效应，即磷对藻吸收砷具有显著的抑制作用.中磷和高磷浓度下，处于延缓期的铜绿微囊藻胞内砷含量高于处于指数增长期胞内砷含量，反映了藻类爆发时对砷的快速代谢外排特征.本研究成果可为认识砷污染与湖泊富营养化之间的相互作用提供科学基础.

• Abstract：The effects of arsenate (As(V)) on the growth and arsenic uptake in Microcystis aeruginosa were determined at different growth phases (lag phase, exponential growth phase and stable phase) and phosphorus (phosphate,P) (0.02 mg·L^-1, 0.1 mg·L^-1 and 0.5 mg·L^-1) levels. Results show that at lag phase, As(V) addition significantly promoted the growth of M. aeruginosa, the average growth rate (μ_2d) increased by 21.49%~32.23% at three phosphorus levels as compared with the control. however, no significant difference was found among the different levels of As(V) treatments. In addition, no effect was seen for phosphorus levels on the growth of M. aeruginosa when As(V) was added in a fixed level. During the exponential growth phase and stable phase, As(V) significantly inhibited the growth of M. aeruginosa, and the inhibitory effect was the highest under the condition of exponential growth phase at 0.02 mg·L^-1 P level, μ_2d linearly decreased with the additions of As(V), with 42.35%~106.30% decreasing as compared with the control, while no effect was observed for As(V) addition on the growth of M. aeruginosa when P was at 0.1 mg·L^-1 and 0.5 mg·L^-1 levels. During the stable phase, the growth of M. aeruginosa gradually decreased with the addition of As(V), the inhibitory effect of As(V) was seen as the pronounced at 0.1 mg·L^-1, and the least at 0.5 mg·L^-1, P levels, the corresponding μ_2d decreased by 1387%~3181% and 15.53%~378.00% as compared with the control, at the former and latter two conditions, respectively. Addition of As(V) significantly promoted the uptake of arsenic in M. aeruginosa cells at different growth phases and at low level phosphorus of 0.02 mg·L^-1, the content of arsenic in cell increased linearly with the addition of As (V). However, such effect became weaken when P was at higher levels as 0.1 mg·L^-1 and 0.5 mg·L^-1, and completely disappeared at the exponential growth phase, suggesting an inhibitory effect of P on As uptake by the algae. At 0.1 mg·L^-1 and 0.5 mg·L^-1 P, arsenic contents in the cell at lag phase was higher than that in the exponential growth phase, indicating a rapid efflux of arsenic with the process of metabolism during the algae bloom. This study has furthered the understanding of the interaction between arsenic pollution and lake eutrophication.

• Key words：lag phase  exponential growth phase  stable phase  linear regression fitting  average growth rate  intracellular arsenic

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