Microbial Fuel Cell Studies of Iron-Oxidising Bacteria
In recent years the bioelectrochemistry of microorganisms has been variously applied to microbial electricity generation,1,2 biomass assay3,4 and biosensing.5,6 Although:these studies have been generally limited to the use of organisms in neutral or near neutral media, the possibilities for exploiting alkalophiles m high pH electrochemical systems was also investigated,7 and the present study formed part of a further exploration of the potential uses of microbial fuel cell techniques under extreme conditions. It focussed on acidophilic species which promote bio-oxidation of arsenopryites (FeAsS) mineral concentrates. This reaction is of importance in a novel gold extraction process in which bacterial oxidation of the arsenical pyrites matrix of refractory gold ores enhances the yield of the metal.8,9 These organisms derivé their energy from the oxidation of reduced sulphur species to sulphate and of Fe(II) to Fe(III), and the latter process was exploited here using a concentration cell in which organisms were placed in the cathode compartment. The electrochemical effects are transmitted by the substrate Fe(II) ions and metabolite Fe(III) ions, which therefore act as mediators. Potentiometric, amperometric and coulometric investigations were conducted as part of a preliminary attempt towards solving one of the problems associated with this technology, namely the assay of bacterial biomass.
KeywordsBiomass Porosity Dioxide Sulphide Phenol
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- 1.H.P. Bennetto, Microbial Fuel Cells, in: Life Chemistry Reports, Vol.2, no.4, eds. A.M. Michelson and J.V. Bannister, (Harwood Acad. Press, London, 1984 ), pp. 363–453Google Scholar
- 2.G. M. Delaney, S. D. Roller, H. P. Bennetto, J. R. Mason,, J. L. Stirling and C. F. Thurston, Microbial Fuel Cells, in: Charge and Field Effects in Biosystems, eds. M. J. Allen and P. N. R. Usherwood ( Abacus Press, Tunbridge Wells, 1984 ) pp. 507–514.Google Scholar
- 4.A.Swain, Rapid microbial assay technology, Ind. Biotechol. 8, 11–15, (1988)Google Scholar
- 5.H. P. Bennetto, J. Box, G. M. Delaney, J. R. Mason, S. D. Roller J. L. Stirling and C. F. Thurston, Redox-mediated electrochemistry of whole microorganisms: from fuel cells to biosensors, in: Biosensors:Fundamentals and Applications, eds. A. P. F. Turner, I. Karube and G. S. Wilson, ( Oxford Univ.Press, Oxford, 1987 ) 291–314.Google Scholar
- 6.D.M.Rawson, Whole cell biosensors, Ind.Biotechnol., 8, 18–22, (1988).Google Scholar
- 8.A.M. Nobar, D.K. Ewart, L. Alsaffar, J. Barrett, M.N. Hughes and R.K. Poole, Isolation and characterisation of a mixed microbial community from an Australian mine: application to the leaching of gold from refractory ores. In Biohydrometallurgy, Proc.Int.Symp., Warwick, 1987, eds. P.R. Norris and D.P. Kelly ( STL, Kew, 1988 ) pp. 530–1.Google Scholar
- 9.A.M.Nobar, D.K.Ewart, L.Alsaffar, J.Barrett, M.N.Hughes and R.K.Poole, Isolation and characterisation of a mixed microbial community from an Australian mine: application to the leaching of gold from refractory ores. In Biohydrometallurgy, Proc.Int.Symp., Warwick, 1987, eds. P. R. Norris and D. P. Kelly ( STL, Kew, 1988 ) pp. 530–1.Google Scholar
- 10.W.J. Ingledew, Bioenergetics of an acidophilic chemolithotroph, Thiobacilluss ferrooxidans. Biochimica and Biophysica Acta, 683, 89–117, (1982).Google Scholar
- 13.S.D.Roller, H.P.Bennetto, G.M.Delaney, J.R.Mason,, J.L.Stirling and C.F.Thurston, Electron-transfer coupling in microbial fuel cells,1; comparison of redox mediator reduction rates and respiratory rates of bacteria, J.Chem.Tech.Biotechnol., 34B, 3–12, (1984).Google Scholar
- 14.G.M.Delaney, H.P.Bennetto, J.R.Mason, S.D.Roller, J.L.Stirling and C.F.Thurston, Electron-transfer coupling in microbial fuel cells,2; performance of fuel cells containing selectred microorganism-mediator-substrate combinations, J.Chem.Tech.Biotechnol., 34B, 3–12, (1984).Google Scholar
- 15.O.H.Lowry, N.J.Rosebrough, A.L.Farr and R.J.Randall; Protein measurement with the folin phenol reagent. J.Biol.Chem. 193, 265–75, (1951).Google Scholar