Abstract:

In order to explore the effect of voltage perturbation on the activities of microorganisms and key enzymes in the metabolic flux of the electrochemical anaerobic digestion(EAD), a single-chamber EAD reactor was used in the experiment, the electrolysis voltage was used as the perturbation variable, and a metabolic model was constructed by using CNA. Quantitative changes are discussed. The results showed that after the voltage disturbance, the methanogenesis pathway was biased towards hydrogenotrophic methanogenesis, accounting for about 38.5%, and the 0.6 V disturbance showed the best methane flux of 0.5222 g. The main sources of H₂ in the EAD system are the cathode and NADH, and the perturbation of the electrolysis voltage will affect the production of H₂, which in turn will affect the methane production flux. After 0.6 V perturbation, the relative abundance of Trichloromonas in the biofilm was as high as 40.2%, which was 1.52 times and 1.13 times that of 1.0 V and 1.4 V, respectively. Meanwhile, CoI, PTA, AK and CoF₄₂₀ all showed the best enzyme activity levels. The activity levels of key enzymes and the relative abundance of Trichloromonas showed good consistency with the methanogenesis flux, and the microbial diversity in the anode biofilm was also an important factor affecting the methanogenesis flux in EAD.

Key words: bioenergy, electrochemical anaerobic digestion, microbial communities, metabolism, enzyme

摘要：

为探究电压扰动对EAD代谢通量中微生物与关键酶活性的影响，实验采用单室EAD反应器，以电解电压为扰动变量，利用CNA构建代谢模型，对扰动前后微生物群落、酶活水平及通量变化进行讨论。结果表明，电压扰动后，产甲烷途径偏向于氢营养型产甲烷，约占38.5%，且0.6 V扰动时表现出最佳的甲烷通量，为0.5222 g。EAD体系中的H₂的主要来源是阴极和NADH，电解电压的扰动会影响H₂的产生，进而会影响产甲烷通量。在0.6 V扰动后，生物膜中Trichloromonas的相对丰度高达 40.2%，分别是1.0 V和1.4 V的1.52倍和1.13倍，同时CoI、PTA、AK与CoF₄₂₀均表现出最佳的酶活水平，关键酶活水平和Trichloromonas的相对丰度与产甲烷代谢通量表现出较好的一致性，而阳极生物膜中微生物多样性也是影响EAD产甲烷通量的重要因素。

关键词: 生物能源, 电化学厌氧消化, 微生物群落, 代谢, 酶