Dunaliella acidophila
Dunaliella asymmetrica
Dunaliella baas
Dunaliella bioculata
Dunaliella carpatica
Dunaliella gracilis
Dunaliella granulata
Dunaliella jacobae
Dunaliella lateralis
Dunaliella maritima
Dunaliella media
Dunaliella minuta
Dunaliella minutissima
Dunaliella parva
Dunaliella peircei
Dunaliella polymorpha
Dunaliella primolecta
Dunaliella pseudosalina
Dunaliella quartolecta
Dunaliella ruineniana
Dunaliella bardawil
Dunaliella terricola
Dunaliella tertiolecta
Dunaliella turcomanica
Dunaliella viridis
Dunaliella is a single-celled, photosynthetic green alga, that is characteristic for its ability to outcompete other organisms and thrive in hypersaline environments.[1] It is mostly a marine organism, though there are a few freshwater species that tend to be more rare.[2] It is a genus in which certain species can accumulate relatively large amounts of β-carotenoids and glycerol in very harsh growth conditions consisting of high light intensities, high salt concentrations, and limited oxygen and nitrogen levels, yet is still very abundant in lakes and lagoons all around the world.
It becomes very complicated to distinguish and interpret species of this genus on simply a morphological and physiological level due to the organism's lack of cell wall that allows it to have malleability and change shape and its different pigments that allows it to change colours depending on the environmental conditions. Molecular phylogeny analysis has become a critical protocol in discovering the taxonomy of Dunaliella.[3] The genus has been studied for over a hundred years,[4] becoming a critical model organism for studying algal salt adaptation processes. It has remained relevant due to its numerous biotechnological applications, including β-carotenoid cosmetic and food products, medicine, and biofuel research.[5]
Dunaliella was originally called Haematococcus salinus by a French botanist named Michel Félix Dunal, who first sighted the organism in 1838 in saltern evaporation ponds in Montpellier, France. However, when the organism was officially described and labelled as a new and distinct genus in 1905 Bucharest, Romania by Emanoil C. Teodorescu, the name was changed to Dunaliella in honour of the original discoverer. To describe the genus, Teodoresco studied live samples from Romanian salt lakes and noted details like colours, movement, and general morphologies.[6]
The genus was also described by another biologist in 1905 named Clara Hamburger in Heidelberg, Germany, but unfortunately Teodoresco’s paper was published first while she was in the final stages of her own article’s production. Hamburger’s description was more thorough since she studied material imported from Cagliari Sardinia and was able to study live as well as dead material and could create sections to view inner cell contents and also described different life stages.[6]
Since then, various other studies on Dunaliella have been performed. Notable ones include Cavara’s article in 1906 expanding on the Cagliari, Sardinia saltern study by Hamburger, Peirce’s article in 1914 on Dunaliella in the Salton Sea, California, Labbé’s various ecological studies of the algae in salterns of Le Croisic, France, Becking et al.’s studies on Dunaliella organisms from all over the world, and in-depth taxonomic studies by Hamel and Lerche.[7][6]