A continuous method for monitoring and controlling fermentations: Using an automated HPLC system

Fermentation processes still lack rapid, reliable, and quantitative methodology for the "real time" analysis of substrates and products. "Real time" data on fermentation components lend itself not only to monitoring complex mixtures, but also to simple control on demand features. An HPLC system has the advantage of being able to discriminate between several different components, usually in less than 15 min, depending on proper column selection. However, samples must be periodically removed from the fermenter, filtered and manually placed in the HPLC injector system for analysis. The system described here uses an automated, computer controlled HPLC system. The unit was fitted with a continous flowthrough sample vial for the on-line analysis of fermentation broths. Results of monitoring a simple yeast fermentation of glucose to ethanol are reported.