Microbial electrosynthesis cathodic communities

Biofilm and suspended communities in microbial electrosynthesis (MES) systems fed with CO2 and acetic acid, at mesophilic conditions (37 C) and pH values of 5 or 6 depending on the sample. The original inoculum was sludge obtained from Lyngby-Taarbaek Wastewater Treatment Plant, which was heat-pretreated to remove methanogens. The pH is a key parameter controlling acetogenesis and chain elongation in gas fermentation and MES studies producing middle-chain fatty acids from CO2. Additionally, in MES systems electron equivalents are provided by the surface of the cathode, and the cathodic biofilm community might therefore be different to the suspended community in the catholyte. The goal of the study was to analyze the microbial community present in the cathode biofilm and suspended in the catholyte of MES systems at pH 5 and pH 6, to compare it with the systems performance and SEM analysis data.