Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China.
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control (CPPC), College of Environment & Ecology, Xiamen University, Xiamen, Fujian 361102, China; Fujian Institute for Sustainable Oceans, Xiamen University, Xiamen, Fujian 361102, China.
Bioresour Technol. 2024 Jul;403:130852. doi: 10.1016/j.biortech.2024.130852. Epub 2024 May 16.
This study effectively coupled anammox and mixotrophic denitrification at a high nitrogen load rate of 6.84 g N/L/d with 40 mg/L Fe(II). Fe(II) enhanced the activity of nitrate reductase, nitrite reductase, and hydrazine dehydrogenase enzymes, facilitating accelerated ATP synthesis. Through electrochemical experiments, interspecies electron transfer processes in coupled system were explored. Fe(II) promoted flavin mononucleotide secretion, enhancing electron-donating and electron-accepting capacity by 2.8 and 1.3 times, respectively. Fe(II) triggered the enrichment of autotrophic denitrifying bacteria (Azospira and Hydrogenophaga), transitioning from single organic nutrient to mixotrophic denitrification. Meanwhile, Fe(II) increased Candidatus_Kuenenia abundance from 35.2 % to 49.0 %, establishing the competitive advantage of anammox bacteria over completed denitrifying bacteria (Comamonas). The synergistic interactions between anammox and various denitrification pathways achieved a nitrogen removal rate of 5.88 g N/L/d, with anammox contribution rate of 88.3 %. This study provides insights into broadening the application of partial denitrification /anammox and electron transfer in multi-bacterial coupling systems.
本研究在高氮负荷率 6.84 g N/L/d 和 40 mg/L Fe(II) 的条件下，有效地将厌氧氨氧化和混合营养型反硝化偶联在一起。Fe(II) 增强了硝酸盐还原酶、亚硝酸盐还原酶和肼脱氢酶的活性，促进了 ATP 的快速合成。通过电化学实验，探索了耦合系统中的种间电子传递过程。Fe(II) 促进黄素单核苷酸的分泌，使电子供体和电子受体的能力分别提高了 2.8 倍和 1.3 倍。Fe(II) 引发了自养反硝化细菌（Azospira 和 Hydrogenophaga）的富集，从单一有机营养物过渡到混合营养型反硝化。同时，Fe(II) 使 Candidatus_Kuenenia 的丰度从 35.2%增加到 49.0%，确立了厌氧氨氧化菌相对于完全反硝化菌（Comamonas）的竞争优势。厌氧氨氧化和各种反硝化途径之间的协同作用实现了 5.88 g N/L/d 的氮去除率，其中厌氧氨氧化的贡献率为 88.3%。本研究为拓宽部分反硝化/厌氧氨氧化和电子传递在多细菌偶联系统中的应用提供了思路。
