太湖水柱中复苏蓝藻对过氧化氢的生理响应研究

Physiological Response of Recruitment Cyanobacteria to Hydrogen Peroxide in Water Column of Taihu Lake

针对蓝藻特有的越冬—复苏生活习性,以春季太湖水柱中复苏蓝藻为研究对象,基于室内模拟研究不同浓度过氧化氢(H2O2)对蓝藻生长的影响及内在机制。结果发现,1mg·L^-1H2O2对复苏蓝藻光合活性的抑制具有时效性,其最大光量子产量和有效光量子产量随着培养时间的延长逐渐恢复。5mg·L^-1H2O2是抑制复苏蓝藻生长的最低有效浓度,对水柱中叶绿素a和藻蓝素的72h去除率分别为60.1%和52.2%,且完全抑制蓝藻的光合活性,降低细胞超氧化物歧化酶和过氧化氢酶的活性,增加细胞内丙二醛含量,破坏细胞的抗氧化系统,对藻细胞膜造成的脂质过氧化是抑制蓝藻生长的内在机理之一。值得注意的是,5mg·L^-1和20mg·L^-1H2O2对水柱中叶绿素a和藻蓝素的去除无显著性差异,因此,建议在藻密度较低的复苏阶段添加低浓度H2O2以降低施用成本及潜在生态风险。本研究可以为科学合理选择控藻时机,优化除藻方案提供理论基础。

Aiming at the overwintering recovery habit of cyanobacteria,this paper takes the recruitment cyanobacteria of Taihu Lake in spring as the research object and talks about the effect of hydrogen peroxide (H2O2)concentration on the growth of cyanobacteria and its inherent mechanism based on lab simulation.It is found that 1 mg·L^-1 H2O2 has a time efficacy on inhibiting the photosynthetic activity of recruitment cyanobacteria and its maximum photon yield and effective photon yield will gradually recover as the cultivation time prolongs.5 mg·L^-1 H2O2 is the lowest concentration that can successfully decrease the growth of recruitment cyanobacteria with a removal rate of 60.1 % for chlorophyll a and 52.2 % at 72 h for phycocyan in water column.A significant decline of photosynthetic yield,activities of superoxide dismutase and catalase,increasing content of malondialdehye in cyanobacteria cells,damage of the cells antioxidant system and lipid peroxidation of algal cell membrane are also observed to be the inherent mechanism for inhibiting the growth of cyanobacteria.It is noteworthy that 5 mg·L^-1 and 20 mg·L^-1 H2O2 have little difference in removing chlorophyll a and phycocyan.Therefore,it is suggested that H2O2 of low concentration should be added at the recruitment stage when the algal density is low so as to reduce the cost and potential ecological risk.It is hoped that the study can provide a theoretic basis for reasonable and scientific timing of algae control and optimization of algae removal scheme.