School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China E-mail:
Water Sci Technol. 2022 Sep;86(5):1269-1283. doi: 10.2166/wst.2022.228.
In this study, we evaluated the relative abundance of nitrogen functional genes (amoA, nirK and nirS) involved in ammonia oxidation and denitrification bacteria in laboratory-scale bioretention columns in response to environmental factors (e.g., moisture content, pH, soil organic matter, soil nitrogen) under different antecedent dry days (ADDs). We observed a decrease tendency of the relative abundance of ammonia-oxidizing bacteria at first and then increased when increasing ADDs from 1 to 22 day, while the relative abundance of denitrifying bacteria showed a downward trend. The abundance of bacteria gene amoA was positively associated with soil ammonia nitrogen concentration (r = 0.389, p < 0.05) and soil organic matter concentration (r = 0.334, p < 0.05), while the abundance of bacteria gene nirS was positively correlated with soil ammonia nitrogen (r = 0.730, p < 0.01), soil organic matter (r = 0.901, p < 0.01) and soil total nitrogen (r = 0.779, p < 0.01). Furthermore, gene counts for bacteria gene nirS were correlated negatively with plant root length (r = 0.364, p < 0.05) and plant biomass (r = 0.381, p < 0.05). Taken together, these results suggest that both nitrification and denitrification can occur in bioretention systems, which can be affected by environmental factors.
在这项研究中，我们评估了实验室规模的生物滞留柱中参与氨氧化和反硝化细菌的氮功能基因（amoA、nirK 和 nirS）的相对丰度，这些基因对不同前干燥天数（ADD）下的环境因素（例如，水分含量、pH 值、土壤有机质、土壤氮）做出响应。我们观察到，随着 ADD 从 1 天增加到 22 天，氨氧化细菌的相对丰度先呈下降趋势，然后增加，而反硝化细菌的相对丰度呈下降趋势。amoA 细菌基因的丰度与土壤氨氮浓度呈正相关（r = 0.389，p < 0.05）和土壤有机质浓度（r = 0.334，p < 0.05），而 nirS 细菌基因的丰度与土壤氨氮呈正相关（r = 0.730，p < 0.01）、土壤有机质（r = 0.901，p < 0.01）和土壤全氮（r = 0.779，p < 0.01）。此外，nirS 细菌基因的基因计数与植物根长（r = 0.364，p < 0.05）和植物生物量（r = 0.381，p < 0.05）呈负相关。总的来说，这些结果表明硝化和反硝化都可以在生物滞留系统中发生，并且可以受到环境因素的影响。
