Microbiome and transcriptomic analysis of cathodic biofilms of MEC and anaerobic granular sludge of an UASB, with DNA and RNA extraction

The main aim of this study was to assess the performance of the biocathode of a lab-scale MEC to convert CO2 into CH4 as a technology for upgrading the biogas produced in anaerobic digesters, comparing two electromethanogenic biomass enrichment strategies: i) direct biomass enrichment in the biocathode of the MEC; ii) external biomass enrichment in a methanol-fed upflow anaerobic sludge blanket reactor (UASB). The evolution of the microbial community was evaluated in terms of composition and activity by the use of quantitative real-time polymerase chain reaction (qPCR) and high throughput sequencing of DNA and RNA.