微生物电解池耦合厌氧消化过程中产甲烷代谢通量与微生物的关系

The relationship between methane production metabolic flux and microorganisms in a microbial electrolytic cell coupled anaerobic digestion

摘要:

为探究微生物电解池耦合厌氧消化（MEC-AD）产甲烷代谢通量与微生物的关系。实验以电压为扰动因子，采用代谢通量分析（MFA）的方法，得到微生物群落与产甲烷通量的响应关系。结果表明：电压扰动后产甲烷通量和产氢通量均发生显著变化，而电压扰动对产乙酸通量的影响较小，其中0.6 V扰动时产甲烷通量最大为0.522±0.051，较对照组1.0 V的0.295±0.013和1.4 V的0.395±0.029分别提高了77%和32%。另外，平均有15.7%±2.9%的H₂（通量）用于还原CO₂产甲烷和乙酸，平均有27.7%±6.9%的乙酸（通量）转化为CH₄。毛螺旋菌（Lachnospiraceae）的丰度对乙酸通量有显著影响，产CH₄通量与理研菌属（Petrimonas）、互营单胞菌属（Syntrophomonas）、拟杆菌属（Blvii28）、假单胞菌属（Acinetobacter）的丰度呈正相关，与梭菌属（Tuzzerella）、球形螺旋菌属（Sphaerochaeta）的丰度呈负相关。而影响产H₂通量和产CH₄通量的物种具有相似性，多为拟杆菌、梭菌、假单胞菌和厚壁菌。此外，物种种间互作关系也是影响MEC-AD产甲烷通量的重要因素。

Abstract:

In this study, voltage was used as a disturbance factor to investigate the relationship between microbial community and methane (CH₄) production flux in a microbial electrolytic cell coupled anaerobic digestion (MEC-AD). Metabolic flux analysis (MFA) was used to explore the relationship between the CH₄ metabolic flux produced and the microbes. The results showed that both methane production flux and hydrogen production flux changed significantly upon voltage disturbance, while the voltage disturbance had little effect on acetic acid production flux. The maximum CH₄production flux under 0.6 V disturbance was 0.522±0.051, which increased by 77% and 32%, respectively, compared with that of the control group under 1.0 V (0.295±0.013) and under 1.4 V (0.395±0.029). In addition, an average of 15.7%±2.9% of H₂ (flux) was used to reduce CO₂ to produce CH₄ and acetic acid, and an average of 27.7%±6.9% of acetic acid (flux) was converted to CH₄. Moreover, the abundance of Lachnospiraceae significantly affected the flux of acetic acid. The flux of CH₄ production is positively correlated with the abundances of Petrimonas, Syntrophomonas, Blvii28, and Acinetobacter, and negatively correlated with the abundances of Tuzzerella and Sphaerochaeta. The species that affected the flux of H₂ and CH₄ were similar, mostly belonging to Bacteroides, Clostridium, Pseudomonas and Firmicutes. Furthermore, the interspecies interaction is also an important factor affecting the MEC-AD methanogenesis flux.