Wang Zhenfang, Yin Sicheng, Chou Qingchuan, Zhou Dong, Jeppesen Erik, Wang Liqing, Zhang Wei
Centre for Research on Environmental Ecology and Fish Nutrient of the Ministry of Agriculture, Shanghai Ocean University, Shanghai, 201306, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, 430072, China.
Environ Pollut. 2022 Feb 1;294:118593. doi: 10.1016/j.envpol.2021.118593. Epub 2021 Dec 2.
Periphyton is considered important for removal of organic pollutants from water bodies, but knowledge of the impacts of antibiotics on the community structure and ecological function of waterbodies remains limited. In this study, the effects of oxytetracycline hydrochloride (OTC) on the communities of photoautotrophic epilithon and epipelon and its effect on nitrogen and phosphorus concentrations in the water column were studied in a 12-day mesocosm experiment. The dynamics of nitrogen and phosphorus concentrations in the epipelon and epilithon experiment showed similar patterns. The concentrations of total nitrogen, dissolved total nitrogen, ammonium nitrogen, total phosphorus and dissolved total phosphorus in the water column increased rapidly during the initial days of exposure, after which a downward trend occurred. In the epilithon experiment, we found that the photosynthesis (Fv/Fm) and biomass of epilithon were significantly (P < 0.05) stimulated in the low concentration group. Contrarily, growth and photosynthesis (Fv/Fm) were significantly (P < 0.05) reduced in the medium and high concentration group. We further found that the photosynthetic efficiency of photoautotrophic epilithon was negatively correlated with the concentrations of nitrogen and phosphorus in the water column (P < 0.05). Principal coordinate analysis (PCoA) showed that the communities of epilithic algae in the control group and in the low concentration group were significantly (P < 0.05) different from that of the high concentration group during the initial 4 days. After 8 days' exposure, all groups tended to be similar, indicating that epilithon showed rapid adaptability and/or resilience. Similar results were found for the relative abundance of some epilithic algae. Our findings indicate that the biofilm system has strong tolerance and adaptability to OTC as it recovered fast after an initial suppression, thus showing the important role of periphyton in maintaining the dynamic balance of nutrients with other processes in aquatic ecosystems.
附生植物被认为对于从水体中去除有机污染物很重要，但关于抗生素对水体群落结构和生态功能影响的认识仍然有限。在本研究中，通过为期12天的中宇宙实验，研究了盐酸土霉素（OTC）对光合自养附石藻和附泥藻群落的影响及其对水柱中氮磷浓度的影响。附泥藻和附石藻实验中氮磷浓度的动态变化呈现出相似的模式。水柱中总氮、溶解态总氮、铵态氮、总磷和溶解态总磷的浓度在暴露初期迅速增加，之后呈下降趋势。在附石藻实验中，我们发现低浓度组附石藻的光合作用（Fv/Fm）和生物量受到显著（P < 0.05）刺激。相反，中高浓度组的生长和光合作用（Fv/Fm）显著（P < 0.05）降低。我们进一步发现光合自养附石藻的光合效率与水柱中氮磷浓度呈负相关（P < 0.05）。主坐标分析（PCoA）表明，在最初的4天里，对照组和低浓度组的附石藻群落与高浓度组的显著（P < 0.05）不同。暴露8天后，所有组趋于相似，表明附石藻表现出快速的适应性和/或恢复力。一些附石藻的相对丰度也有类似结果。我们的研究结果表明，生物膜系统对OTC具有很强的耐受性和适应性，因为它在最初受到抑制后恢复迅速，从而显示了附生植物在维持水生生态系统中营养物质与其他过程动态平衡方面的重要作用。
