Salt induced changes in the growth of Chlorococcum humicolo and Scenedesmus bijugatus under nutrient limited cultures

Chlorococcum humicolo and Scenedesmus bijugatus showed optimal growth at 41.06 and 20.53 mM sodium chloride, respectively. However, compared to the control in pure pond water, the salinity of 5.13-82.12 mM caused growth enhancement of C. humicolo while for S. bijugatus the range was 5.13-41.06 mM until the seventh day and 5.13-20.53 after 15 d in nutrient enriched cultures. In normal tank water the range for S. bijugatus was 5.13-20.53 and 5.13-10.27 mM after 7 and 15 d, respectively, while for C. humicolo it remained unchanged. The growth rates at all salinity levels increased rapidly during the first 7 d. In S. bijugatus, the growth rates at different salinities were significantly different from each other in nutrient enriched medium, while in pond water the growth rates between 5.13 and 10.27 mM and 41.06-82.12 mM were not significant. In C. humicolo the growth varied significantly at all but 10.27-20.53 mM in nutrient added cultures. The significance of the results are discussed.