Characterization of a new electrochemically active bacterium, Lysinibacillus sphaericus D-8, isolated with a WO3 nanocluster probe

• A new EAB was identified using a WO3 nanocluster probe.
• The strain was designated as Lysinibacillus sphaericus D-8 based on 16S rDNA sequencing.
• Electrochemical activity was characterized with a two-chamber MFC and EIS.
• CV analysis suggested an indirect extracellular electron transfer taken by this strain.

Microorganisms capable of extracellular electron transfer play important roles in biogeochemical redox processes and have been of great interest in the fields of energy recovery, waste treatment, and environmental remediation. In this study, a new electrochemically active bacterium was identified with a high-throughput method using WO3 nanoclusters as probes. The 16S rRNA gene sequence designated the strain as Lysinibacillus sphaericus D-8, a Gram-positive bacterium. Its electrochemical activity was characterized in a two-chamber microbial fuel cell and a three-electrode electrochemical cell. Strain D-8 produced 92 mW/m2 of power using lactate as the electron donor. The electrochemical impedance spectroscopy results confirmed the electrochemical activity of this strain. Cyclic voltammetry analysis indicated that the presence of soluble redox active compounds might play an important role in the extracellular electron transfer by L. sphaericus D-8. This work might be the first report that demonstrates the electrochemical activity of Lysinibacillus species.