The Effect of Different Salinities on Density of Spirulina plaetensis under Laboratory Conditions

This research conducted with five treatments of salinity of 15, 20, 25, 30 and 35 ppt on culture of S. plaetensis. Comparing the average of density of the species under treatments revealed that the least density is at salinity of 35 ppt. A significance difference was at the level of 5% comparing to other treatments. The most density was obtained in treatment of 15 ppt. The most cellular density was for 15, 20 and 25 ppt and salinities of 30 and 35 ppt rated 4th and fifth respectively. Relying on above statements, one may come up with this conclusion that cellular density of S. plaetensis is less in lower salinities than that of higher salinities. Upon raise of degree of salinity, growth of the species shall decrease. In other words, in its natural habitation, this species tolerate higher salinity. However, the nature of the species is more compatible with lower salinity.