Electrochemical Microwell Plate to Study Electroactive Microorganisms in Parallel and Real-Time

Area of Science:

• Microbiology
• Electrochemistry
• Bioengineering

Background:

• Screening electroactive microorganisms (EAMs) for microbial resource mining is challenging due to a lack of suitable electrochemical tools.
• Existing methods are often low-throughput, limiting the discovery and characterization of novel EAMs.

Purpose of the Study:

• To develop and validate a novel electrochemical microwell plate (ec-MP) system for high-throughput screening of EAMs.
• To investigate the electrochemical and metabolic properties of EAMs, including pure cultures and co-cultures.
• To link microbial electrochemical performance to genetic and abundance shifts.

Main Methods:

• Development of an ec-MP integrating a 96-well plate with a 96-channel multipotentiostat.
• Electrochemical cultivation and characterization of *Shewanella oneidensis* and *Geobacter sulfurreducens* pure cultures.
• Co-cultivation experiments with varying electron donors (acetate, lactate) and individual well genetic analysis.

Main Results:

• The ec-MP system successfully achieved high maximum current densities (j_max) and coulombic efficiencies (CE) for pure cultures, consistent with literature.
• Co-cultivation of *S. oneidensis* and *G. sulfurreducens* significantly increased j_max (up to 99.36 ± 19.12 µA cm⁻²).
• Co-cultures exhibited reduced time to reach maximum current and biphasic current production, correlated with shifts in microbial relative abundance.

Conclusions:

• The developed ec-MP is a powerful tool for advancing microbial resource mining and the characterization of EAMs.
• Co-cultivation strategies using the ec-MP system can enhance microbial electrochemical performance.
• This technology facilitates the link between microbial community dynamics and electrochemical activity, paving the way for optimized bioelectrochemical systems.