Investigations are carried out with Clostridium sp. which is isolated from sugar industry effluents, as a biocatalyst for current generation in a microbial fuel cell. Two different configurations of the cell are evaluated. In both cells, the anode compartment consists of suspended cells of Clostridium sp. in a nutrient broth in a phosphate buffer. In the first configuration, the cathode compartment consisted of ferricyanide solution (0.05 M). In the second configuration, the cathode compartment consisted of cells of Thiobacillus ferrooxidans suspended in a nutrient broth. The second configuration represents a complete microbial cell with the anodic and cathodic reactions driven by micro-organisms. The performance characteristics of the two configurations are evaluated with two different anode materials, graphite and graphite felt. (c) 2006 Elsevier B.V. All rights reserved.