Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
College of Chemistry and Chemical Engineering, Xinjiang Normal University, Urumqi 830054, China.
Int J Environ Res Public Health. 2022 Feb 10;19(4):1994. doi: 10.3390/ijerph19041994.
Benthic biofilms are pioneering microbial aggregates responding to effluent discharge from wastewater treatment plants (WWTPs). However, knowledge of the characteristics and linkage of bacterial communities and water-soluble organic matter (WSOM) of benthic biofilms in effluent-receiving rivers remains unknown. Here, we investigated the quality of WSOM and the evolution of bacterial communities in benthic biofilm to evaluate the ecological impacts of effluent discharge on a representative receiving water. Tryptophan-like proteins showed an increased proportion in biofilms collected from the discharge area and downstream from the WWTP, especially in summer. Biofilm WSOM showed weak humic character and strong autochthonous components, and species turnover was proven to be the main factor governing biofilm bacteria community diversity patterns. The bacterial community alpha diversity, interspecies interaction, biological index, and humification index were signally altered in the biofilms from the discharge area, while the values were more similar in biofilms collected upstream and downstream from the WWTP, indicating that both biofilm bacterial communities and WSOM characters have resilience capacities. Although effluent discharge simplified the network pattern of the biofilm bacterial community, its metabolic functional abundance was basically stable. The functional abundance of carbohydrate metabolism and amino acid metabolism in the discharge area increased, and the key modules in the non-random co-occurrence network also verified the important ecological role of carbon metabolism in the effluent-receiving river. The study sheds light on how benthic biofilms respond to effluent discharge from both ecological and material points of view, providing new insights on the feasibility of utilizing benthic biofilms as robust indicators reflecting river ecological health.
底栖生物膜是对污水处理厂（WWTP）排放的废水做出响应的先驱微生物聚集体。然而，对于废水接收河流中底栖生物膜的细菌群落特征和水溶性有机物（WSOM）的联系，我们知之甚少。在这里，我们研究了 WSOM 的质量和底栖生物膜中细菌群落的演变，以评估废水排放对代表性受纳水体的生态影响。色氨酸样蛋白在来自排放区和 WWTP 下游的生物膜中表现出增加的比例，尤其是在夏季。生物膜 WSOM 显示出较弱的腐殖质特征和较强的自生源成分，物种更替被证明是控制生物膜细菌群落多样性模式的主要因素。来自排放区的生物膜的细菌群落 α多样性、种间相互作用、生物指数和腐殖化指数都发生了显著变化，而 WWTP 上游和下游采集的生物膜中的值则更为相似，这表明生物膜细菌群落和 WSOM 特征都具有恢复能力。尽管废水排放简化了生物膜细菌群落的网络模式，但它的代谢功能丰度基本保持稳定。排放区碳水化合物代谢和氨基酸代谢的功能丰度增加，非随机共现网络中的关键模块也验证了碳代谢在废水接收河流中的重要生态作用。该研究从生态和物质的角度揭示了底栖生物膜对废水排放的响应，为利用底栖生物膜作为反映河流生态健康的稳健指标提供了新的见解。
