Dunaliella salina (Chlorophyceae) Affects the Quality of NaCl Crystals

Abstract The green alga Dunaliella salina is a common inhabitant of crystallizers in solar saltworks. Although its presence has been associated with low salt quality, little is known about the mechanism through which Dunaliella causes such effect. It has been suggested that the release of organic matter from healthy D. salina cells interferes with NaCl crystallization. With the intention to cast some light on this matter, we grew D. salina cells at different [NaCl] (0.3, 1.0, 2.0 and 3.0 M), in the presence of either NO3- or NH4+, in conditions that, although strongly hyperaline, were mild enough to minimize cell lysis and substantial spill over of cytosolic sap. The two N treatments were done because the N-source was shown to influence organic release from D. salina. We then attempted to link this physiological information to the information to the quality of NaCl crystals. In order to reduce the impact of inter-crystal inclusion and focus on the structure of the crystalline reticulum, the volume of wate...