Jiang Xiaofeng, Zuo Shengpeng, Ye Liangtao, Hong Wenxiu
a College of Environmental Science and Engineering , Anhui Normal University , Wuhu , People's Republic of China.
Environ Technol. 2019 Feb;40(6):693-700. doi: 10.1080/09593330.2017.1404135. Epub 2017 Nov 21.
Nanomaterials and/or contaminants are becoming more common in the developing world, but their effects on interspecific interactions are rarely reported, particularly in aquatic ecosystems. Thus, the present study determined the effects of the novel pollutant nano-fumed silica (NFS) on algal control by a macrophyte via the allelochemical p-hydroxybenzoic acid in a microcosm test. The allelochemical p-hydroxybenzoic acid caused significant decreases in chlorophyll a, but increased the amount of superoxide anion radicals ( ) and the electric conductivity in Microcystis aeruginosa. The 50% inhibitory concentration (IC) for p-hydroxybenzoic acid was 0.919 mmol/L in microalga during the exponential phase. Interestingly, NFS at 100-1600 mg/L had clear stimulatory effects on M. aeruginosa. When NFS at 800 mg/L was combined with different concentrations of p-hydroxybenzoic acid, the IC for p-hydroxybenzoic acid was 1.045 mmol/L. Thus, NFS significantly reduced the algicidal effect exhibited by p-hydroxybenzoic acid on M. aeruginosa. Furthermore, NFS might act as a silicon nutrient and enhance allelopathic resistance in M. aeruginosa to inhibit the algicidal effects of macrophytes via allelopathy. These findings suggest that before algal control is considered using macrophyte allelopathy, it is essential to remove the pollutant NFS from polluted lakes.
纳米材料和/或污染物在发展中国家正变得越来越普遍，但其对种间相互作用的影响却鲜有报道，尤其是在水生生态系统中。因此，本研究通过微宇宙试验，确定了新型污染物纳米气相二氧化硅（NFS）对大型植物通过化感物质对羟基苯甲酸控制藻类的影响。化感物质对羟基苯甲酸导致铜绿微囊藻叶绿素a显著降低，但超氧阴离子自由基（ ）含量和电导率增加。在指数生长期，微藻中对羟基苯甲酸的50%抑制浓度（IC）为0.919 mmol/L。有趣的是，100 - 1600 mg/L的NFS对铜绿微囊藻有明显的刺激作用。当800 mg/L的NFS与不同浓度的对羟基苯甲酸联合使用时，对羟基苯甲酸的IC为1.045 mmol/L。因此，NFS显著降低了对羟基苯甲酸对铜绿微囊藻的杀藻作用。此外，NFS可能作为硅营养物质，增强铜绿微囊藻的化感抗性，从而通过化感作用抑制大型植物的杀藻作用。这些发现表明，在考虑利用大型植物化感作用控制藻类之前，必须从受污染的湖泊中去除污染物NFS。
