Using of an Artificial Biofilm for the Characterization of Direct Transfer of Electrons by Thillobacillus Denitrificans

Thiobacillus denitrificans named T. denitrificans is a Gram negative anaerobic bacteria and obligately chemolithoautotrophic it reduces metal ions, because his metabolism essentially uses periplasm reductase. Multiheme cytochrome transmit electrons to insoluble reductases as the terminal acceptors on the membrane surface or soluble reductases [1]. We are studying the capacity of T. denitrificans to catalyze fumarate and fumarate electro reduction. For that, we used an artificial biofilm. Made of carbon nanotubes and living cells which is used as the working electrode in electrochemical cell under permanent nitrogen flow. All experiments are performed in the potential range from +0.2V to -0.8V/Ag/AgCl.  The experiments show that T. denitificans has capacity to participate to direct electron transfer associated to the targeted reactions.  The temperature is an important factor; at 30°C the signal of reduction is more pronounced than at the room temperature. E. coli and Pseudomonase are have been using in this stady as control,