Monitoring of fermentations with online capacitance sensor

In biotechnological experiments the development and kinetics of the microbial culture are crucial information. Therefore researchers made lot of efforts to develop different cell measuring systems. Classically offline methods were widely used but they do not give real-time and reliable results enough. Among them some are able to follow even the living cell-number, which has probably the highest importance. A new, innovative online living-cell measurement sensor (InCyte (Hamilton) were received from Hamilton Bonaduz AG to test it with different art of microorganism. In the present investigation we elaborated a method for preliminary sensor application test, which is more fast and simple than testing this sensor directly in real cultivations. We already tested InCyte sensor with a prokaryotic lactobacillus (Lactobacillus sp.) and with eucaryotic yeast (Saccharomyces cerevisiae) furthermore with a microalgae strain (Chlorella vulgaris), which latter is also eukaryotic as well. We could confirm, that in some cases only high cell density could result high signal enough for the sensor, but according to our findings, InCyte sensor is applicable even for microalgae. Furthermore via conductivity measurements it can give information on product formation, too