This study describes the effects of graphene oxide (GO) and reduced graphene oxide (rGO) on the acetoclastic, hydrogenotrophic and methylotrophic pathways of methanogenesis by an anaerobic consortium. The results showed that GO negatively affected the hydrogenotrophic and acetoclastic pathways at a concentration of 300 mg/L, causing a decrease of ~ 38% on the maximum specific methanogenic activity (MMA) with respect to the controls lacking GO. However, the presence of rGO (300 mg/L) promoted an improvement of the MMA (> 45%) achieved with all substrates, except for the hydrogenotrophic pathway, which was relatively insensitive to rGO. The presence of either rGO or GO enhanced the methylotrophic pathway and resulted in an increase of the MMA of up to 55%. X-ray photoelectron spectroscopy (XPS) analysis revealed that GO underwent microbial reduction during the incubation period. Electrons derived from substrates oxidation were deviated from methanogenesis towards the reduction of GO, which may explain the MMA decreased observed in the presence of GO. Furthermore, XPS evidence indicated that the extent of GO reduction depended on the metabolic pathway triggered by a given substrate.

中文翻译：

---

氧化石墨烯和还原氧化石墨烯对碎裂，氢营养和甲基营养的甲烷生成的影响。

这项研究描述了氧化石墨烯（GO）和还原的氧化石墨烯（rGO）对厌氧财团产甲烷菌的产甲烷，营养和甲基营养途径的影响。结果表明，GO浓度为300 mg / L时会对氢营养和乙酰碎裂途径产生负面影响，相对于缺乏GO的对照，最大比产甲烷活性（MMA）降低〜38％。但是，rGO（300 mg / L）的存在促进了所有底物的MMA（> 45％）的改善，除了对rGO相对不敏感的氢营养途径。rGO或GO的存在增强了甲基营养途径，并导致MMA的增加高达55％。X射线光电子能谱（XPS）分析表明，GO在潜伏期经历了微生物还原。源自底物氧化的电子从甲烷生成转向GO还原，这可以解释在GO存在下观察到的MMA降低。此外，XPS证据表明GO减少的程度取决于给定底物触发的代谢途径。