A closed system for outdoor cultivation of Porphyridium

Abstract Experience accumulated during the past few years indicates that the main problems in the large-scale cultivation of algae in open ponds are low productivity and contamination. Thus, the use of closed systems can be an alternative method of cultivation. In the present study, a closed system made of polyethylene sleeves was compared with open ponds with respect to growth and polysaccharide production of two species of Porphyridium: Porphyridium sp. and P. aerugineum. For both species, cell number, biomass, and polysaccharide production were higher in the sleeves than in the ponds. It seems that polyethylene sleeves have the following advantages over open ponds: high light availability, high rate of heating and cooling, improved turbulence, relative lack of contamination, and prevention of evaporation and hence of fluctuation in salinity.