Liu Haoyu, Xu Ying, Li Lei, Li Xinyu, Dai Xiaohu
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Water Res. 2024 Nov 15;266:122331. doi: 10.1016/j.watres.2024.122331. Epub 2024 Aug 24.
The enhancement of electron or proton transfer between syntrophic microbes has been widely recognised as a means for improving methane generation. However, the uncoupled supplementation of electrons and protons in multiphase anaerobic environment hinders the balanced uptake of electrons and protons in the cytoplasm of methanogens, limiting methanogenesis efficiency. Herein, the cooperative effect of a proton-conductive material (PM) and an electron-conductive material (EM) in enhancing proton-coupled electron transfer (PCET) and driving efficient methanogenesis in anaerobic digestion was investigated. The cooperation of the PM and EM significantly increased methane production and the maximum methane generation rate by 78.9 % and 103.5 %, respectively, indicating enhanced methanogenesis efficiency. Analysis of the physicochemical properties, biochemical components, and microbial dynamics revealed that the cooperation of the PM and EM improved the metabolism of syntrophic microbes, which was critically dependent on electron and proton transfer. This enhancement was primarily due to the improvement in PCET, as mainly supported by hydrogen/deuterium kinetic isotope effect measurements, multi-omics integration analyses and reaction thermodynamics and kinetics analyses. Our findings suggest that the PCET enhancement stimulated efficient membrane-bound enzymatic reactions related to electron-driven proton translocation and facilitated electron and proton supply for CO reduction to realise highly efficient methane generation. These findings are expected to provide a new insight into effective electron and proton coupling transfer for methanogenic metabolism in multiphase anaerobic environments.
互营微生物之间电子或质子传递的增强已被广泛认为是提高甲烷生成的一种手段。然而，在多相厌氧环境中电子和质子的非耦合补充阻碍了产甲烷菌细胞质中电子和质子的平衡摄取，限制了甲烷生成效率。在此，研究了质子传导材料（PM）和电子传导材料（EM）在增强质子耦合电子转移（PCET）和驱动厌氧消化中高效甲烷生成方面的协同作用。PM和EM的协同作用分别使甲烷产量和最大甲烷生成速率显著提高了78.9%和103.5%，表明甲烷生成效率得到提高。对物理化学性质、生化成分和微生物动态的分析表明，PM和EM的协同作用改善了互营微生物的代谢，这关键取决于电子和质子传递。这种增强主要归因于PCET的改善，氢/氘动力学同位素效应测量、多组学整合分析以及反应热力学和动力学分析主要支持了这一点。我们的研究结果表明，PCET增强刺激了与电子驱动质子转运相关的高效膜结合酶促反应，并促进了电子和质子供应以将CO还原为甲烷，从而实现高效甲烷生成。这些研究结果有望为多相厌氧环境中产甲烷代谢的有效电子和质子耦合转移提供新的见解。
