Sustainable bioelectricity production from Amaranthus viridis and Triticum aestivum mediated plant microbial fuel cells with efficient electrogenic bacteria selections

[Display omitted] •Food crop plant microbial fuel cell (PMFC) was developed for electricity production.•PMFC Triticum aestivum produced highest current density (185.23 ± 15.10 mA/m2).•The organic-rich bioslurry enhanced the power output up to 291.23 ± 7.50 mA/m2.•Biofilm analysis and phylogenetic tree reveals the role of rhizobacteria in PMFCs. Application of plant-mediated Microbial fuel cell (PMFC) for bioelectricity production with food crop yield has not yet been appropriately investigated. This study aims to reveal the ability of two essential food plants: Amaranthus viridis (P1) and Triticum aestivum (P2), for sustainable bioenergy production and food harvest for 180 days consecutively. The study showed that the highest power density obtained from P2-PMFC was higher than the P1-PMFC, and the organic-rich nutrient called bioslurry in PMFCs shows twofold intensification in the electrochemical reaction. The main role of bioslurry (brown gold) as a magical organic-rich nutrient increases the plant growth and the activity of electrogenic bacteria in PMFCs. Thus the current density of P1 (114.52 ± 20.05 mA/m2) and P2 (185.23 ± 15.10 mA/m2) without bioslurry was increased with a maximum current density of 185.23 ± 15.10 mA/m2 (P1) and 291.23 ± 7.50 mA/m2 (P2) with bioslurry. The high content screening technique and scanning electron micrograph confirm the biofilm formation on the rhizosphere-anode region of both the plants. Culturable rhizosphere-anode region bacterial species were isolated in P1 and P2 PMFCs, and their electrogenic activity was confirmed using the single-chambered Microbial fuel cells (MFCs) through polarization test. The constructed phylogenetic tree for the 31 isolates concludes the diversity of all bacterial species, of which the phylum Firmicutes dominates in both PMFCs. The individual polarization curve efficiency of the isolates ranges from 7.62 to 194.45 mW/m2, and among the 31 isolates, Hydrogenophaga sp. JBP18, Pseudomonas aeruginosa JBP1, Ralstonia sp. JBP24, Ochrobactrum intermedium strain JBP22 and Bacillus safensis JBP6 were selected as potential electrogenic bacteria. Accordingly, this study might lead to the development of MFC technology for sustainable electricity production using food crop plants and determining more rhizosphere-anode electrogenic bacterial species in the future.