Growth monitoring of a photosynthetic micro-organism (Spirulina platensis)by pressure measurement

An on-line measurement technique for estimating biomass production rate in a photosynthetic micro-organism culture was developed and tested experiment ally. The technique is based on monitoring O-2 production from the increase in pressure inside a closed photobioreactor. The data obtained by this met hod correlated with the direct measurement of the biomass concentration. A material balance on the components in the system allows the validity domain of the method to be defined. The method was applied to batch cultures of t he cyanobacterium, Spirulina platensis, in a cylindrical photobioreactor va lidating existing physiological and light energy models.