ELECTRICITY PRODUCTION IN AQUATIC BEDS WITH ELECTRO-ACTIVE BACTERIA

FIER GUIDO; BONANNI P. SEBASTIAN; SCHROTT GERMÁN D.; BUSALMEN JUAN PABLO

Congreso; X CONGRESO ARGENTINO DE MICROBIOLOGÍA GENERAL; 2014

SAMIGE

Electro-active bacteria can use a polarized electrode as the final electron-acceptor of their respiratory chain. In this way, they can couple degradation of organic compounds and production of electric current. These bacteria are present in most sedimentary environments where they use simple carbon compounds (such as acetate) as carbon and electron source and metallic oxides as electron acceptor. Typically, the activity of these bacteria is limited by the availability of metallic oxides in the media. This limitation can be overcome by introducing polarized electrodes in the sediment that can act as electron acceptor. This leads to the formation of an electro-active biofilm on the electrode surface which produces a stable electric current directly from the bacterial metabolic activity. This energy can be used to operate marine-deployed instruments with lower maintenance requirements and lower cost than the alkaline batteries normally used in those devices. We have studied the production of electricity by electro-active bacteria from natural aquatic environments replicated in the laboratory at small scale. We have tested different electrode materials and configurations and achieved a design that produces almost 50mW per m2 of submerged electrode. This energy would allow charging Li-ion batteries as those typically used in mobile devicesor operate a meteorological bouy with a few square meters of electrode.