COMMUNICATIONS TO THE EDITOR ELECTROCHEMICAL PH CONTROL OF SACCHAROMYCES-CEREVISIAE BATCH CULTURES

The pH of batch cultures of Saccharomyces cerevisiae NCYC 1018 was controlled either chemically with 4N NaOH and 4N HCl or electrochemically by making the fermentor either the anode or cathode of an electrochemical cell. The maximum specific growth rate achieved was similar ( mu equals 0. 21) with both control systems, but the yield of biomass from glucose, total biomass produced, and total glucose utilized were all less in the chemically pH-controlled fermentations. Electrochemical pH control has the advantages that the volume and the ionic composition of the medium change less than with chemical pH control. This article describes the development of an electrochemical pH control system.