Abstract:
Dunaliella is a green halotolerant microalga, which has several industrial applications
e.g. β-carotene production. Identification of different Dunaliella species has been carried
out by morpho-physiological and recently molecular studies. To achieve an improved
understanding of taxonomy, these studies are required to be in linkage. The present study
describes molecular and specific morpho-physiological properties of a Dunaliella isolate
obtained from Gavkhooni salt marsh in Iran. Phylogenetic analysis of Internal
Transcribed Spacer region demonstrated that the isolate was associated with different
species except D. salina (CCAP 19/18 and 19/30) and D.viridis. 18S rDNA size of the
isolate was identical to that of D. tertiolecta and intron-lacking strains of D. salina. 18S
rDNA fingerprint profile and phylogenetic analysis revealed D. tertiolecta as the closest
taxon to the isolate. Features of optimum growth salinity (1.5-3% w/v) and maximum
carotenoid per cell (0.7 pg cell-1) were comparable with reported data for D. terrtiolecta.
Morphological characteristics including the size and color of the cells, presence and
location of stigma and refractile granules were similar to those of D. tertiolecta. Totally,
considering molecular and morpho-physiological properties, the isolate was attributed to
the species D. tertiolecta and was named as Dunaliella tertiolecta ABRIINW-G3.
Keywords: Carotenoid, Dunaliella, 18S rDNA, Internal Transcribed Spacer, Optimum
growth salinity.
