Anaerobic Bioelectrochemical Microbial Cultivation. Anaerobic Microbial Consortia

Metabolic activities of a microbial consortium, before and after being exposed to an electrochemical process for the degradation of azo dye methyl orange were studied. The process was carried out in a Microbial Electrolysis Cell type reactor, applying J=0.0016 mA cm-2, 0.2 V. Dye removal kinetics, Chemical Oxygen Demand and Total Nitrogen were analyzed and the results were related to the consortium's metabolic activities and relative abundance of the microbial species sequenced through the V3-16S rRNA region. An increase in dye removal by 27% was achieved for the bioelectrochemical process; here, metabolic stages of hydrolysis and acidogenesis were predominant. In addition, the main population change that resulted after the application of electric current was the increase of Proteobacteria from the genus Acinetobacter and Klebsiella as well as Firmicutes from the genus Lactococcus.