The performance and biomass enrichment of the biocathode of a pair of lab-scale two-chambered microbial electrolysis cells (MEC) were assessed for 95 days as a technology for upgrading the biogas produced in anaerobic digesters, converting CO₂ into CH₄ through the electromethanogenic process. Two different inocula were compared: (i) a mixture of biomass from the anode of a MEC and anaerobic granular sludge (BC1); (ii) biomass enriched in a methanol-fed upflow anaerobic sludge blanket reactor (UASB) (BC2). Quantitative and qualitative microbial community assessment of the enrichment process on the biocathodes was performed by means of high-throughput sequencing of 16S rDNA- and 16S rRNA-based massive libraries as well as RT-qPCR of 16S rRNA and mcrA genes. Although BC2 had a faster increase in current density than BC1, there were no significant differences neither in the average CH₄ production (0.23 ± 0.01 and 0.22 ± 0.05 L m^–3 day^–1 for BC1 and BC2, respectively) nor in the cathodic methane recovery efficiency (65 ± 8% and 79 ± 17%, respectively). Independently from the origin of the inoculum, total and active archaeal microbial community in both biocathodes was dominated by hydrogenotrophic methanogenic archaea, especially belonging to Methanobacteriaceae family (mainly Methanobrevibacter genus) (84–98% of both 16S rDNA and 16S rRNA relative abundance).

中文翻译：

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带有两种不同生物量接种物的沼气转化用电甲烷产生微生物电解池的启动

评估了一对实验室规模的两室微生物电解池（MEC）的生物阴极的性能和生物质富集度，为期95天，该技术可用于升级厌氧消化池中产生的沼气，并通过电甲烷产生将CO ₂转化为CH _4。过程。比较了两种不同的接种物：（i）来自MEC阳极的生物质和厌氧颗粒污泥（BC1）的混合物；（ii）富含甲醇的上流厌氧污泥床反应器（UASB）（BC2）中富集的生物质。通过高通量测序基于16S rDNA和16S rRNA的大量文库以及RT-qPCR对生物阴极的富集过程进行了定量和定性的微生物群落评估。16S rRNA和mcrA基因。尽管BC2的电流密度增加快于BC1，但平均CH ₄产量（BC1和BC2分别为0.23±0.01和0.22±0.05 L m ^–3天^–1天）和阴极均无显着差异。甲烷回收效率（分别为65±8％和79±17％）。独立于接种物来源，两个生物阴极中的总和活动古细菌微生物群落均以氢营养型产甲烷古细菌为主，尤其是属于甲烷杆菌科（主要是甲烷短杆菌属）（16S rDNA和16S rRNA的84–98％） 相对丰度）。