For decades, D. salina has been cultivated for its natural ability to produce |3-carotene. This valuable bioproduct allows for large-scale cultivation and processing of the biomass to be very profitable, as D. salina is the predominant source of natural |3-carotene (Ye et al. 2008). This green alga is ideal for growth in outdoor ponds due to its ability to grow in high salinity waters — as much as eight times the salt concentration of seawater — greatly reducing the threat of contamination by local microbes and eliminating the need for large quantities of freshwater. Dunaliella spp. are similar to Chlamydomonas spp. in that they exist as single, flagellated, elongated cells in the size range of 10 microns; however, D. salina and D. tertiolecta, are capable of osmoregulation by a complex network of ion channels, a flexible cell membrane uninhibited by a cell wall, and glycerol biosynthesis to offset osmotic pressure (Goyal, 2007). As such, the lack of a rigid cell wall makes the algal biomass relatively simple to lyse for the purpose of downstream processing. Furthermore, the technique of "milking" microbial cells for certain metabolites has improved substantially in recent years. In this process, the cells are contacted with a biocompatible organic solvent in order to promote preferential transfer of desired compounds to the solvent phase, leaving the cells viable for continued bioproduction. This process has been successfully demonstrated with D. salina for the extraction of |3-carotene in a two-phase system (Hejazi et al, 2004b).

While the demand for natural |3-carotene dictates the high market price of this compound and continued use of D. salina, an increasing desire for biofuel production draws an inquisitive eye to the carotenogenesis pathways of D. salina (Lamers et al., 2004). Since all carotenoid compounds are composed of long-chain branched hydrocarbons, it is conceivable that the biosynthetic pathways of D. salina could be altered to produce hydrocarbons that are ideal for use as gasoline-like biofuel. With some molecular biology tools already developed for Dunaliella spp. (Polle et al., 2009), the sequencing and annotation of its 610 Mbp nuclear genome will now allow for more extensive genetic engineering endeavors with this organism. At the time of these experiments, only the chloroplast and mitochondrial genomes of D. salina CCAP 19/18 (GenBank GQ250046, GQ250045) were released. In light of its unique biotechnological application and long history of mass production, D. salina is an ideal organism for future development as a biofuel producing microalgae.