Improved biomass production of cyanobacteria by reutilization of the culture medium

The biomass production of a cyanobacterium (Nostoc sp.) in a photoreactor with a low illuminated surface area to volume ratio was improved by the reutilization of the culture medium. After six succesive utilizations the growth ofNostoc sp. amounted to 2.15 g/l with an average content in phycobiliproteins of 14.4% on dry weight basis. The procedure reported allowed an 80% increase in biomass. The cellular self-sedimentation proved to be effective for biomass separation between reutilization steps.