Microbial Fuel Cell Based on Nitrogen-Fixing Rhizobium anhuiense Bacteria

Abstract

In this study, the nitrogen-fixing, Gram-negative soil bacteria Rhizobium anhuiense was successfully utilized as the main biocatalyst in a bacteria-based microbial fuel cell (MFC) device. This research investigates the double-chambered, H-type R. anhuiense-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−2 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−2 estimated at an operating voltage of 281 mV. The R. anhuiense-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−2. The influence of different concentrations of MD on the viability of R. anhuiense bacteria was investigated by estimating the optical density at 600 nm (OD600) 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 R. anhuiense bacteria cells remain viable and act as a main biocatalyst for MFC applications.

An Analysis of Global Trends from 1990 to 2022 of Microbial Fuel Cells: A Bibliometric Analysis

“…While the fields in the lower right quadrant are emerging or quasi-isolated topics, their evolution will depend on discoveries that are made in the short term. According to the reviewed literature, it will depend on the investigations on the microorganisms isolated in different types of waste, as these microorganisms are being used as a substrate (fuel) to observe their potential to generate bioelectricity in MFCs, where electrolytic reduction plays an important role for the generation of ions and electrons [75,76].…”

“…Thus, microorganisms isolated from different types of waste are also being studied. These microorganisms are being used as a substrate (fuel) to observe their potential to generate bioelectricity in MFCs [75,76].…”

Anode Modification with Fe2O3 Affects the Anode Microbiome and Improves Energy Generation in Microbial Fuel Cells Powered by Wastewater

“…occurred in the anode biofilm, which all have been reported to be involved in energy generation in MFCs. The Rhizobium anhuiense strain is an effective EE and generated a maximum voltage of 635 mV and output power of 1.07 mW/m 2 in a glucose-fed dual-chamber MFC operated in an open circuit [77]. Thiovirga sp.…”

Isolation and Characterisation of Electrogenic Bacteria from Mud Samples

“…Today, the number of isolated electroactive bacteria is increasing. Therefore, the number of bacteria that are found to be capable of carrying out direct or indirect electron transfer is also increasing [ 19 , 20 , 21 , 22 , 23 ]. This knowledge broadens the spectrum of known electrogenic bacteria with different metabolic and enzymatic capacities, and based on that knowledge, special microbial consortia can be established that can degrade simple [ 24 , 25 ] or more complex substrates, such as cellulose, lignin or proteins [ 11 , 26 ].…”