Methanol solvents that are used in hydraulic fracturing often return back to the surface in the form of recalcitrant flowback water. Here, the indigenous methylotrophic bacteria from flowback water were enriched and used to generate electricity from methanol in a two-compartment microbial fuel cell (CH3OH-MFC). An identical MFC based on a tryptone-yeast extract (TY-MFC) was used as a control. CH3OH-MFC yielded a 2.7-fold thicker biofilm dominated by electrogenic species (81%) and higher power density (76 mW/m2) compared with TY-MFC (50 mW/m2). Illumina MiSeq sequencing of the 16S rRNA gene in TY-MFC revealed classes from Actinobacteria, Bacteroidia and γ-proteobacteria. The CH3OH-MFC yielded α-proteobacteria, β-proteobacteria, γ-proteobacteria and Bacteroidia, with a dominant fraction of Rhodobacter sphaeroides (~29%). We discuss the potential pathways used by R. sphaeroides to maintain syntrophic cooperation with other bacterial and archaeal members to sustain CH3OH oxidation. Finally, we establish that a pure culture of R. sphaeroides 2.4.1 generates electricity directly from methanol.

中文翻译：

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甲醇利用水力压裂返排水中的天然甲基营养物从甲醇中获得电力。

在水力压裂中使用的甲醇溶剂通常以顽固性回流水的形式返回地面。在这里，来自回流水的本地甲基营养细菌得以富集，并用于在两室微生物燃料电池（CH3OH-MFC）中由甲醇发电。基于胰蛋白tone-酵母提取物的相同MFC（TY-MFC）用作对照。与TY-MFC（50 mW / m2）相比，CH3OH-MFC产生的生物膜厚2.7倍，被电原性物种（81％）支配，功率密度更高（76 mW / m2）。TY-MFC中16S rRNA基因的Illumina MiSeq测序揭示了来自放线菌，细菌和γ-变形杆菌的类别。CH3OH-MFC产生α-变形杆菌，β-变形杆菌，γ-变形杆菌和拟杆菌，其中球形红球菌占主导地位（〜29％）。我们讨论了潜在的途径，由R. sphaeroides维持与其他细菌和古细菌成员的营养合作以维持CH3OH氧化。最后，我们确定纯球形球菌2.4.1的培养物直接从甲醇中发电。