Effect of salinity on the growth of the cyanobacterium Spirulina platensis in monoculture and mixed cultures

The effect of NaCl concentrations on the growth of the cyanobacterium Spirulina platensis in monoculture and in mixed culture with the green halophilic alga Dunaliella salina was studied. The,growth rate of S. platensis in monoculture did not change within the salinity range from 1 to 20 g/l NaCl. With an increase in salinity, the growth rate declined, and, at 70 g/l NaCl, the cyanobacteria died. The response of S. platensis to changes in salinity in mixed culture with D. salina did not differ from that observed in monoculture. At a concentration of 50 g/l NaCl these species of microorganisms could coexist.