Enrichment of Anode-Respiring Bacteria Using an On-Site Electrochemical System

Abstract

Source: Okamoto, A., et al. Self-standing Electrochemical Set-up to Enrich Anode-respiring Bacteria On-site. J. Vis. Exp. (2018)

This video demonstrates the use of an on-site electrochemical system to enrich anode-respiring bacteria (ARB) from natural reservoirs. A redox gradient is established by placing the anode in oxygen-free deep water and the cathode in oxygen-rich surface water. ARB form biofilms and transfer electrons to the anode, which flows to the cathode, where oxygen is reduced, generating current. The anode is collected under anaerobic conditions for downstream analysis.

Protocol

1. Collection of the Electrode Sample from the Natural Environment

1. To prevent the quality of the anode sample from being damaged due to oxygen contamination, collect the electrode under anaerobic conditions.
2. At least 30 minutes prior to collecting the electrode sample, put a test tube in an anaerobic location. For example, put the test tube and lid separately at the bottom of the pond to make the inside of the bottle anaerobic.
3. Cut the titanium lead from the electrode with a wire cutter, gently collect the electrode sample into the test tube, and seal it in the anaerobic water zone. To keep the sample fresh, store the sample at 4 °C immedia....

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Carbon felt sheet	n/a	n/a	Used for anode and cathode
Titanium wire	The Nilaco Cooporation	TI-451485	Used to construct fuel cell system
Graphite epoxy	Electrolytica lnc.	n/a	Used to connect the electrodes and Ti wire
Resistor	Sodial		Used to construct fuel cell system
Conducting wire	Pico	81141s	Used to construct fuel cell system
Voltmeter and Data logger	T&D corporation	VR-71	Used for data recording