On-line monitoring of lipolytic activity by sequential injection analysis

An automated sequential injection analysis using stop-flow technique for th e on-line determination of lipolytic activity has been developed. It is bas ed on a colorimetric method using a chromogenic substrate, 1,2-O-dilauryl-r ac-glycero-3-glutaric acid-(6-methylresorufin)-ester. The system permits a linear range analysis between 5-100 lipolytic activity units ml(-1), withou t external dilution of the sample, a sampling frequency of 5 samples per ho ur and a relative standard deviation (RSD) of 5%. The analyser has been use d for the on-line monitoring of Candida rugosa fed-batch fermentation with excellent performance, regarding its reliability and reproducibility.