Visualization Isolation of Electrochemically Active Bacteria by Using a Gelled Electrode-Based Electrochemical Plate

Electrochemically active bacteria (EAB) are catalysts of microbial electrogenesis and electrosynthesis, showing great prospects in wastewater treatment and biochemical engineering. However, isolating EAB is difficult, and only a few pure-cultured EAB have been reported. In this study, a novel gelled electrode based on an electrochemical plate is established, which for the first time realizes the selective screening of EAB strains and visible colony formation. A new EAB, Rhodococcus qingshengii C6, is isolated by using the method. R. qingshengii C6 is capable of electricity generation with a wide range of substrate spectra and is capable of reducing common electron acceptors by consuming electricity. The bidirectional extracellular electron transfer mechanism is preliminarily investigated, and exogenous redox mediators play an important role in extracellular electron transfer. This study provides an easy and simple method for the isolation and purification of EAB, contributing to the valuable bacterial resources exploration.