Comparative bioelectrochemical analysis of Pseudomonas aeruginosa and Escherichia coli with anaerobic consortia as anodic biocatalyst for biofuel cell application

Aims: To study the bioelectrochemical behaviour of Pseudomonas aeruginosa (MTCC 17702) and Escherichia coli (MTCC 10436) and to assess their potential to act as anodic biocatalyst with the function of anaerobic consortia for microbial (bio) fuel cell (BFC) application. Methods and Results: Three BFCs (single chamber; open-air cathode; noncatalysed electrodes) were operated simultaneously in acidophilic microenvironments. Pseudomonas aeruginosa (BFCP) showed higher current density (264 mA m-2) followed by mixed culture (BFCM; 166 mA m-2) and E. coli (BFCE; 147 mA m-2). However, total operating period and substrate degradation were relatively found to be effective with mixed culture (58%; 72 h) followed by BFCP (39%; 60 h) and BFCE (31%; 48 h). Higher electron discharge (ED) was observed with Ps. aeruginosa while mixed culture showed the involvement of redox mediators in the ED process. Conclusions: Mixed culture showed to sustain biopotential for longer periods along with a stable ED. The presence of redox signals and high substrate degradation was also evidencing its performance compared to the pure strains studied. This supports the practical utility of mixed culture over the pure cultures for real-field BFC applications especially while operating with wastewater. Significance and Impact of the Study: This study revealed the efficiency and viability of mixed consortia in comparison with pure strains for microbial (bio) fuel cell applications.