Sources of Conductance Changes during Bacterial Reduction of Trimethylamine Oxide to Trimethylammonium in Phosphate Buffer

Department of Food Technology, University of Reading, Whiteknights, PO Box 226, Reading RG6 2AP, UK ABSTRACT The sources of conductance changes during reduction of trimethylamine oxide to trimethylamine by Escherichia coli with formate as electron donor and in the presence of phosphate buffer were investigated. Theoretical considerations and experimental results suggest that the major source of conductance change is the conversion of dihydrogen phosphate to hydrogen phosphate. This transformation contributes almost twice as much to the total conductance change as does the conversion of uncharged trimethylamine oxide to charged trimethylammonium. Present address: Departamento de Alimentos. Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico. Present address: North Lindsey College of Technology, Kingsway, Scunthorpe, UK.