Ethanol utilization by sulfate-reducing bacteria: An experimental and modeling study

A mixed culture of sulfate-reducing bacteria containing the species Desulfo vibrio desulfuricans was used to study sulfate-reduction stoichiometry and kinetics using ethanol as the carbon source. Growth yield was lower, and ki netics were slower, for ethanol compared to lactate. Ethanol was converted into acetate and no significant carbon dioxide production was observed. A m athematical model for growth of sulfate-reducing bacteria on ethanol was de veloped, and simulations of the growth experiments on ethanol were carried out using the model. The pH variation due to sulfate reduction, and hydroge n sulfide production and removal by nitrogen sparging, were examined. The m odeling study is distinct from earlier models for systems using sulfate-red ucing bacteria in that it considers growth on ethanol, and analyzes pH vari ations due to the product-formation reactions. (C) 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 533-543, 2000.