PHYLOGENETIC STUDY OF SOME STRAINS OF <i>DUNALIELLA</i>

Abstract

<i>Dunaliella</i> strains were isolated from a key site for salt production in Vietnam (Vinh Hao, Binh Thuan province). The strains were identified based on Internal Transcribed Spacer (ITS) markers. The phylogenetic tree revealed these strains belong to the clades of <i>Dunaliella salina</i> and <i>Dunaliella viridis</i>. Results of this study confirm the ubiquitous nature of <i>Dunaliella</i> and suggest that strains of <i>Dunaliella salina</i> might be acquired locally worldwide for the production of beta-carotene. The identification of these species infers the presence of other <i>Dunaliella</i> species (<i>Dunaliella tertiolecta</i>, <i>Dunaliella primolecta</i>, <i>Dunaliella parva</i>), but further investigation would be required to confirm their presence in Vietnam. We anticipate the physiological and biochemical characteristics of these local species will be compared with imported strains in a future effort. This will facilitate selection of strains with the best potential for exploitation in the food, aquaculture and biofuel industries. The <i>Dunaliella</i> strains isolated and identified in this study are maintained at the Laboratory of Algal Biotechnology, International University and will be made available for research and educational institutions

Dunaliella viridis TAV01: A Halotolerant, Protein-Rich Microalga from the Algarve Coast

“…A few sequences did not fall into of these three clades, namely that of D. acidophila and a sequence classified as belonging to D. pseudosalina (KU641615). As previously described by other authors [43], classifying a novel Dunaliella strain down to the species level is notoriously difficult. However, our results do support the idea that the genus Dunaliella has been subdivided into more species than the molecular data suggests [24].…”

Utility of the pat gene as a selectable marker gene in production of transgenic Dunaliella salina

“…Therefore, possible errors in taxonomic assignments have been reported when they are only based on morphological analyses (Borowitzka and Siva, 2007;Tran et al 2013). The ITS region of the 18S rRNA gene and the large subunit of the ribulose bisphosphate carboxylase gene (rbcL) are widely used as effective molecular tools in microalgal characterization and biodiversity studies (Preetha et al, 2012).…”

Microalgal Classification

“…At the light microscopical level, the freshwater alga C. vulgaris is a fairly nondescript round nonmotile reproductive cell ranging in size from 2 to 10 mm with a single chloroplast, containing amylose and amylopectin-based starch granules, a single pyrenoid containing high amounts of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) for CO 2 fixation (Safi et al, 2014). Cell shape and size vary, but shape is typically oval (4e15 mm wide and 6e25 mm long) under good growth conditions, becoming round under unfavorable environmental or growth conditions (Tran et al, 2013). The cell wall develops in complexity with cell age being tougher in older cells, with glucosamine incorporation providing cell wall rigidity, but sporopollenin incorporation was also reported when grown heterotrophically (Martinez et al, 1991;Safi et al, 2014).…”