AUTOMATED MONITORING OF BIOTECHNOLOGICAL PROCESSES USING ONLINE ULTRAFILTRATION AND COLUMN LIQUID-CHROMATOGRAPHY

The efficient control of fermentation processes requires reliable moni toring systems. This paper describes a fully automated monitoring syst em based on the on-line combination of ultrafiltration and column liqu id chromatography. An evaluation of the performance of a hollow-fibre ultrafiltration module is provided and a method for the determination of sugars, alcohols and organic acids during a gluconic acid and a bee r fermentation is presented. The system can be used for at least 250 h with complex fermentation broths under both aerobic and anaerobic con ditions without any detrimental effect on either the fermentation or t he chromatographic part. Depending on the application 3-5 analyses can be performed every hour, using only 3.0 mul of sample per analysis. U sing refractometric or direct UV detection the linear dynamic range is from 0.2 to 150 g l-1 for most of the compounds, while with a simple post-column derivatization procedure sugars can be determined in the l ow mg l-1 range.