OPTICAL SENSORS FOR FERMENTATION PROCESSES

Abstract

In spite of the great effort of chemical engineers today the on-line measurement in fermentation processes is still limited to physical and chemical quantities. The most important biological parameters, such as biomass, substrate, product or metabolites are still not accessible to on-line measurements. As a company strongly involved in the development and production of measurement equipment for bioprocesses, Ingold Messtechnik AG started a few years ago a research program directed to the development of on-line sensors for biological parameters. For the following reasons an approach using the optical measurement technology has been considered as the most promising one: - The optical measurement technology has at least for laboratory use already reached a very high and sophisticated standard. The future developments of optical components such as semiconductor detectors or fiber optics will certainly increase the versatility of this technique. - There are many compounds of biological origin which can be directly measured by optical methods (e.g. absorption, fluorescence attenuated total reflection). - The combination of optical methods with chemical mediator substances would allow to measure also physical or chemical parameters such as pH or oxygen concentration. The use of enzymes and/or fluorescence labelled antibodies would allow to make this technique highly versatile.