Cultivation of Electrogens With Cost‐Effective Membrane‐Less Bioreactor Designs

ABSTRACT Rational improvements in bioreactor design for scaling up power generation in microbial fuel cells (MFCs) are discussed in this study. The potential of autoclavable MFCs for isolating electroactive bacteria that produce sustainable electricity is being investigated. Dual‐chamber sterilizable fuel cells were constructed to evaluate the electrogenic performance of microorganisms collected from marine environments. Voltage generation was monitored using multimeters, and electrogens were identified through 16S rRNA sequencing. Two‐chambered fuel cell systems were upgraded to single‐chambered configurations, which effectively reduced electrode spacing and internal resistance. The bioreactor designs incorporated natural alternatives for expensive ion exchange membranes. Anoxygenic phototrophic bacteria (APBs), known for their ability to generate electrons under anaerobic conditions without oxygen evolution, were investigated as potential electrogens. These bacteria are primarily found in the genera Rhodobacter , Rhodopseudomonas , Rubrivivax , and Chloroflexus . Marine environments are appealing for mining electrogenic bacteria within APBs. Given their likely evolution from marine origins, local beach areas of the Bay of Bengal were investigated using a metagenomic approach to identify potential sources rich in electrogenic bacteria. Distinct electrogenic bacterial colonies exhibited differential electrogenicity despite being isolated from the same source. The proposed cost‐effective, scalable, and membrane‐less designs demonstrate improved power output and hold promise for sustainable energy generation and wastewater treatment applications.