Monitoring biomass and glycerol in an Escherichia coli fermentation using near-infrared spectroscopy

Near-infrared spectroscopy was used to determine biomass and glycerol concentrations in E. coli whole broth fermentation samples. For dry cell weight, a standard error of prediction (SEP) of 0.2 g/L and correlation coefficient (r) of 0.991 were obtained. The SEP and r for glycerol, carbon nutrient, were 0.3 g/L and 0.979, respectively. Off-line analysis was accomplished within 2 minutes of sampling and therefore provides the opportunity to monitor fermentations quickly enough to permit in-process development and troubleshooting.