Microbial Fuel Cell Based on Nitrogen-Fixing Rhizobium anhuiense Bacteria

• Published in: Biosensors (Basel) Vol. 12; no. 2; p. 113
• Main Authors: Žalnėravičius, Rokas, Paškevičius, Algimantas, Samukaitė-Bubnienė, Urtė, Ramanavičius, Simonas, Vilkienė, Monika, Mockevičienė, Ieva, Ramanavičius, Arūnas
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.02.2022; MDPI
• Subjects: Agriculture; Anodes; Bacteria; Biocatalysts; Biochemical fuel cells; Bioelectric Energy Sources - microbiology; Carbon; Carbon sources; Cell membranes; Charge transfer; Chloride; Circuit design; Electricity distribution; Electrodes; Energy; Fertilizers; Fuel cells; Fuel technology; Gene expression; Genetic engineering; Glucose; Gram-negative bacteria; Investigations; Legumes; Maximum power; Menadione; microbial fuel cells; Microorganisms; Nitrogen; Nitrogen fixation; Nitrogen-Fixing Bacteria; Nitrogenation; Open circuit voltage; Optical density; Potassium; Potassium ferricyanide; Power; Rhizobium; Rhizobium anhuiense; Sodium; Soil bacteria; Soil microorganisms; Substrates; Voltage; Lithuania; Rhizobium anhuiense; nitrogen-fixing bacteria; microbial fuel cells; menadione
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios12020113

In this study, the nitrogen-fixing, Gram-negative soil bacteria was successfully utilized as the main biocatalyst in a bacteria-based microbial fuel cell (MFC) device. This research investigates the double-chambered, H-type -based MFC that was operated in modified Norris medium (pH = 7) under ambient conditions using potassium ferricyanide as an electron acceptor in the cathodic compartment. The designed MFC exhibited an open-circuit voltage (OCV) of 635 mV and a power output of 1.07 mW m with its maximum power registered at 245 mV. These values were further enhanced by re-feeding the anode bath with 25 mM glucose, which has been utilized herein as the main carbon source. This substrate addition led to better performance of the constructed MFC with a power output of 2.59 mW m estimated at an operating voltage of 281 mV. The -based MFC was further developed by improving the charge transfer through the bacterial cell membrane by applying 2-methyl-1,4-naphthoquinone (menadione, MD) as a soluble redox mediator. The MD-mediated MFC device showed better performance, resulting in a slightly higher OCV value of 683 mV and an almost five-fold increase in power density to 4.93 mW cm . The influence of different concentrations of MD on the viability of bacteria was investigated by estimating the optical density at 600 nm (OD ) and comparing the obtained results with the control aliquot. The results show that lower concentrations of MD, ranging from 1 to 10 μM, can be successfully used in an anode compartment in which bacteria cells remain viable and act as a main biocatalyst for MFC applications.