Dunaliella salina - Overview

                Dunaliella salina

• Dunaliella salina is a unicellular microalgae belong to division Chlorophyta .
  
  
  
• It is found in salinity environments such as salted brines, salt evaporation ponds, and hypersaline lakes .It is able to tolerate varying NaCl concentrations, ranging from 0.2% to approximately 35% . Thus, Dunaliella salina is a hyper-halotolerant organism found in high densities in saline lakes. 
• The ability to tolerate high salt concentrations is advantageous, since competition is minimal in high salt concentration areas. 

How D.salina tolerate high salt concentration?

• D. salina has adapted to survive in high salinity environments by accumulating glycerol to balance osmotic pressure.
• Note : D. salina is also adapted to solar radiation using β-carotene to protect against ionizing energy.

       

        Red Colour of Salt Brines 

• Dunaliella salina was thought to be responsible for the red colouring of salted brines . However, carotenoids responsible for the red colouration in D. salina are found in algal chloroplasts, whereas halophilic archaea also occupying hypersaline lakes have red pigments dispersed throughout the cell membrane . Although there is a much greater abundance of D. salina, the red pigments on the cell membrane of archaea are more visibly accessible. Therefore, D. salina has a much less overall impact to colouration and archaeal communities contribute more to the red colouration of hypersaline lakes.

 

         Reproduction in D. salina

• Dunaliella salina can reproduce asexually, sexually and through division of motile vegetative cells. Sexual reproduction, the formation of two gametes into a zygospore, is affected by salt concentration. Martinez et al determined the sexual activity of "D. salina" from evaluating ratio of zygotes and zygospores to total cells observed in culture. Low salt concentrations of 2% and 5% induced sexual activity, whereas higher salt concentration of 30% decreases sexual reproduction.

                       Uses of D. sanila

•  D. sanila is used as a model organism to study the effect of salt concentration on algae.
• Known for its antioxidant activity because of its ability to create large amount of carotenoids, it is used in cosmetics and dietary supplements.
• Glycerol in D. salina as a key organic compatible solute has been used as a research model .