Microalgae-assisted microbial fuel cells for electricity generation coupled with wastewater treatment: Biotechnological perspective

Recently, a lot of research work has been performed on microalgal-assisted microbial fuel cells (MFCs) for electricity generation, wastewater treatment, and biomass production. However, a comprehensive investigation on the insight of microalgal-assisted MFCs along with a deep discussion on the application of molecular biology approaches has not been reviewed yet. In this review, the state-of-the-art on efficient use of microalgae (alive/non-alive biomass) in MFCs based on the strategy of mono-culturing, co-culturing, and substrate (microalgae and bacteria symbiosis) has been discussed. The major concerns in microalgal-assisted MFCs (such as microbial strains selection, cultivation mode, stress tolerance, inoculum ratio, and expensive separators) with the potential solutions (including replacement of expensive separators, and optimization of process parameters) have been emphasized. The genetic modification strategies (gene knock-in and gene knock-out) combined with transcriptomics, proteomics, and metabolomics under the stress conditions to enhance the potential of microalgal-assisted MFCs for electricity generation and microalgal biomass production have been highlighted. The recent studies where the scale-up was applied for the commercialization of microalgal-assisted MFCs technology and techno-economic feasibility (comparison of laboratory and scale-up unit price) have been elucidated. This review addresses an outlook of the microalgal-assisted MFCs biotechnology along with the symbiosis of microalgae/bacteria in MFCs and could be useful to the key processes and practical applications.