Characterization of species within the green algal genus Dunaliella.

Dionne Avery, Claudeline Louis and Juergen E.W. Polle

Department of Biology, Brooklyn College of CUNY, 2900 Bedford Ave. 200NE, Brooklyn, NY 11210, USA

Halotolerant unicellular green algae of the genus Dunaliella are among the few commercially used microalgae. Currently, there are about 28 unicellular green algal species described that fall within the genus Dunaliella. 5 freshwater and 23 saltwater species are recognized for the genus Dunaliella. Until a few years ago, morphological and physiological characteristics have been the major criteria for species distinction. Unfortunately, cell morphology depends largely on environmental factors such as salinity and age of the cell culture. Because of great morphological variation even within one species, there has been confusion as to the correct classification of various described species and subspecies. Only recently has additional molecular analysis of the number of introns within the 18s rDNA gene as well as sequence analysis of the nuclear internal transcribed spacer 1 and 2 regions (ITS1 and ITS2) been used to classify species of the genus Dunaliella. Here we present the current status of sequence analysis to further delineate Dunaliella species and subspecies of the sectio Viridae from each other.