Relative effect of bioaugmentation with electrochemically active and non-active bacteria on bioelectrogenesis in microbial fuel cell

[Display omitted] •Enhancement of electrogenesis after bioaugmentation.•Improved performance due to synergistic interaction between native culture and EAB.•FISH analysis tracked survivability of augmented strains.•Augmented strains showed twofold increase in capacitance/exchange current density. Bioelectrogenic activity of microbial fuel cells (MFC) augmented with electrochemically active bacteria (EAB, Pseudomonas aeruginosa) and non-EAB (Escherichia coli) as biocatalysts was investigated. Anodic microflora augmented with P. aeruginosa (AMFCP) yielded higher electrogenic activity (418mV; 3.87mA) than E. coli (AMFCE; 254mV; 1.67mA) and non-augmented native microflora (MFCC; 235mV; 1.37mA). Higher redox currents along with lower Tafel-slopes were observed with AMFCP operation compared to AMFCE and MFCC due to manifestation of bioaugmentation thereby minimizing the losses. A fourfold and twofold increase in capacitance and exchange current was observed with AMFCP and AMFCE operation respectively, when compared to MFCC. Tracking of augmented biocatalyst by fluorescent in situ hybridization (FISH) with defined probes documented the survivability of Pseudomonas sp. in higher numbers than Enterobacteriaceae. Study corroborated enhanced electron transfer capability of mixed consortia owing to the synergistic interaction with EAB due to augmentation.