Integrated analysis of microbial growth and energy storage behavior in bacterial electrochemical systems

Understanding the relationship between microbial growth behavior and electrochemical performance is critical for the development of bio-hybrid energy-storage systems. In this study, four bacterial species representing distinct ecological and physiological classes—Escherichia coli, Vibrio natriegens, Ruegeria pomeroyi DSS-3, and Limnohabitans planktonicus—were systematically evaluated to establish a direct correlation between growth kinetics and energy-storage characteristics.
Growth behavior was quantified using optical density, viable cell counts, and direct cell enumeration, enabling accurate determination of exponential growth rates, biomass accumulation, and growth-phase transitions across species. Significant differences in growth kinetics were observed, with Vibrio natriegens exhibiting the highest specific growth rate and Limnohabitans planktonicus displaying the slowest and lowest-amplitude growth profile.
Following growth characterization, each organism was integrated into a standardized three-electrode electrochemical platform to evaluate charge-storage behavior using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The results revealed substantial interspecies variation in electrochemical performance, with Vibrio natriegens demonstrating the highest capacitance and discharge capability, while Limnohabitans planktonicus showed minimal response due to limited biomass and weaker interfacial coupling.
Correlation of growth and electrochemical datasets showed that energy-storage performance depends on both biomass availability and organism-specific interfacial properties. While rapid growth and high biomass generally enhance electrochemical output, intrinsic physiological characteristics govern charge-transfer behavior and capacitive response.
This work establishes a unified framework linking microbial growth dynamics to electrochemical functionality and provides a basis for selecting and engineering bacterial systems for bio-hybrid energy-storage applications.