Enrichment of Chromium-Reducing Bacteria Using Potential-Controlled Electrochemical Cultivation
We present here a method for the electrochemical enrichment of chromium-reducing bacteria from environmental samples containing various microorganisms. An electrochemical cultivation system was constructed; this consisted of a Pt anode and a carbon cathode separated by an ion-exchange membrane. For an electrochemical cultivation, an environmental sample with chromium-reducing bacteria was inoculated into the anode well where a medium containing 0.1 mM Cr(VI) ions was poured. On the other hand, Cr(VI)-free medium was poured into the cathode well. Chromium-reducing bacteria grew selectively after 10 days of incubation and application of 1.0 V (vs. Ag/AgCl) of anode potential that reproduces Cr(VI) ions. This result suggested that Cr(VI) ions generated on the anode promoted the growth of chromium-reducing bacteria as their electron acceptor and due to Cr(VI) toxicity, inhibited the growth of other microorganisms.
Axel Schippers, Wolfgang Sand, Franz Glombitza and Sabine Willscher
N. Matsumoto et al., "Enrichment of Chromium-Reducing Bacteria Using Potential-Controlled Electrochemical Cultivation", Advanced Materials Research, Vols. 20-21, pp. 505-508, 2007