AUTHOR=Kuchenbuch Anne , Frank Ronny , Ramos José Vazquez , Jahnke Heinz-Georg , Harnisch Falk 

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

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.821734

DOI=10.3389/fbioe.2021.821734

ISSN=2296-4185

ABSTRACT=<p>Microbial resource mining of electroactive microorganism (EAM) is currently methodically hampered due to unavailable electrochemical screening tools. Here, we introduce an electrochemical microwell plate (ec-MP) composed of a 96 electrochemical deepwell plate and a recently developed 96-channel multipotentiostat. Using the ec-MP we investigated the electrochemical and metabolic properties of the EAM models <italic>Shewanella oneidensis</italic> and <italic>Geobacter sulfurreducens</italic> with acetate and lactate as electron donor combined with an individual genetic analysis of each well. Electrochemical cultivation of pure cultures achieved maximum current densities (<italic>j</italic><sub>max</sub>) and coulombic efficiencies (<italic>CE</italic>) that were well in line with literature data. The co-cultivation of <italic>S. oneidensis</italic> and <italic>G. sulfurreducens</italic> led to an increased current density of <italic>j</italic><sub>max</sub> of 88.57 ± 14.04 µA cm<sup>−2</sup> (lactate) and <italic>j</italic><sub>max</sub> of 99.36 ± 19.12 µA cm<sup>−2</sup> (lactate and acetate). Further, a decreased time period of reaching <italic>j</italic><sub>max</sub> and biphasic current production was revealed and the microbial electrochemical performance could be linked to the shift in the relative abundance.</p>