Alternative start-up strategies for the Bioelectrosynthesis of acetate
Área de conocimiento
Datos de la obra
10th World Congress of Chemical of Ingeneering, 1st-5th October, 2017
Carbon capture and utilization at biocathodes provides a solution to minimize CO2 emissions meanwhile commodity chemicals are being generating from an inexpensive substrate. The aim of this work is to develop biocathodes for MES systems capable of making use of CO2 in order to generate valuable chemicals. The biocathodes were inoculated using two different inocula and following two different strategies. These different start-up conditions showed distinct electrical behavior in three of the four cases. These microbial electro-synthesis systems (MES) were capable of achieving an acetic acid production between 70-196mg/L depending on the strategy. The use of a river mud inoculum resulted in a sharp enrichment, and when the potential was invert to force it to work as a biocathode, the biofilm got mostly specific in acetic acid producing bacteria, Acterobacteraceae, and some hydrogen generating bacteria. The hydrogenotrophic methanogen Methanobacteriaceae, was the only family identified on the cathode. However, the use of an anaerobic digestion inoculum resulted in a highly diverse biofilm and in a lower acetic acid production with hydrogen detected. The Archaeal population was inhibited under this condition. To conclude it is observed that specialisation of biofilm in certain Eubacterial families improves bioelectrosynthesis, and acetic acid production in particular. In addition, it is highlighted that being the Archaeal community quite similar within both biofilms, the dominant families on the cathode biofilms were drastically different, likely due to the difference in the Eubacterial microorganisms. Thanks “Junta de Castilla y Leon” for postdoctoral contract associated to project ref: LE060U16. The authors acknowledge the funding of the Spanish “Ministerio de Economía y Competitividad” via project CTQ2015-68925-R.