Dong Tingjun, Zhang Li, Hao Shiwei, Yang Jiachun, Peng Yongzhen
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing, 100124, China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing, 100124, China.
Water Res. 2024 May 15;255:121532. doi: 10.1016/j.watres.2024.121532. Epub 2024 Mar 26.
Photocatalytic materials-microbial biohybrid systems pave the way for solar-driven wastewater nitrogen removal. In this study, interspecies cooperation in photogenerated electron transfer and efficient nitrogen removal mechanism in the g-CN-anammox consortia biohybrid system were first deciphered. The results indicated that the essential extracellular electron carriers (cytochrome c and flavin) for anammox genomes were provided by associated bacteria (BACT3 and CHLO2). This cooperation, regulated by the ArcAB system and electron transfer flavoprotein, made anammox bacteria the primary photogenerated electron sink. Furthermore, an efficient photogenerated electron harness was used to construct a reductive glycine pathway (rGlyP) in anammox bacteria inventively, which coexisted with the Wood-Ljungdahl pathway (WLP), constituting a dual-pathway carbon fixation model, rGlyP-WLP. Carbon fixation products efficiently contributed to the tricarboxylic acid cycle, while inhibiting electron diversion in anabolism. Photogenerated electrons were targeted channeled into nitrogen metabolism-available electron carriers, enhancing anammox and dissimilatory nitrate reduction to ammonium (DNRA) processes. Moreover, ammonia assimilation by the glycine cleavage system in rGlyP established an alternative ammonia removal route. Ultimately, multi-pathway nitrogen removal involving anammox, DNRA, and rGlyP achieved 100 % ammonia removal and 94.25 % total nitrogen removal efficiency. This study has expanded understanding of anammox metabolic diversity, enhancing its potential application in carbon-neutral wastewater treatment.
光催化材料-微生物生物杂交系统为太阳能驱动的废水脱氮铺平了道路。在本研究中，首次解析了g-CN-厌氧氨氧化菌聚生体生物杂交系统中光生电子转移的种间合作及高效脱氮机制。结果表明，厌氧氨氧化菌基因组必需的细胞外电子载体（细胞色素c和黄素）由相关细菌（BACT3和CHLO2）提供。这种由ArcAB系统和电子转移黄素蛋白调节的合作，使厌氧氨氧化菌成为主要的光生电子汇。此外，利用高效的光生电子利用途径，在厌氧氨氧化菌中创造性地构建了一条还原甘氨酸途径（rGlyP），该途径与伍德-Ljungdahl途径（WLP）共存，构成了双途径碳固定模型rGlyP-WLP。碳固定产物有效地促进了三羧酸循环，同时抑制了合成代谢中的电子转移。光生电子被定向引导到氮代谢可用的电子载体中，增强了厌氧氨氧化和异化硝酸盐还原为铵（DNRA）的过程。此外，rGlyP中甘氨酸裂解系统的氨同化建立了一条替代的氨去除途径。最终，涉及厌氧氨氧化、DNRA和rGlyP的多途径脱氮实现了100%的氨去除率和94.25%的总氮去除效率。本研究扩展了对厌氧氨氧化代谢多样性的理解，增强了其在碳中和废水处理中的潜在应用。
