Molecular and phylogenetic analysis reveals new diversity of Dunaliella salina from hypersaline environments

Andrea Highfield,Richard Pipe,Declan C Schroeder,Angela Ward

doi:10.1017/s0025315420001319

Abstract

AbstractTwelve hyper-β carotene-producing strains of algae assigned to the genus Dunaliella salina have been isolated from various hypersaline environments in Israel, South Africa, Namibia and Spain. Intron-sizing of the SSU rDNA and phylogenetic analysis of these isolates were undertaken using four commonly employed markers for genotyping, LSU rDNA, ITS, rbcL and tufA and their application to the study of Dunaliella evaluated. Novel isolates have been identified and phylogenetic analyses have shown the need for clarification on the taxonomy of Dunaliella salina. We propose the division of D. salina into four sub-clades as defined by a robust phylogeny based on the concatenation of four genes. This study further demonstrates the considerable genetic diversity within D. salina and the potential of genetic analyses for aiding in the selection of prospective economically important strains.

Highlights

Dunaliella (Chlorophyceae, Dunaliellales) is a genus of algae with immense economic potential owing to its production of an array of exploitable compounds, including β-carotene, glycerol and phytosterols
Microscopy clearly identified cells that had accumulated β-carotene owing to the orange-red colouration and those affiliated to the section Dunaliella, species D. salina (Figure 1)
The culture collection legacy of this strain continues as two other culture collections host this strain as the same as the original D. bardawil isolated by Ben-Amotz and Avron

Summary

Introduction

Dunaliella (Chlorophyceae, Dunaliellales) is a genus of algae with immense economic potential owing to its production of an array of exploitable compounds, including β-carotene, glycerol and phytosterols (reviewed by Avron & Ben-Amotz, 1992). Species within this genus include halophilic and halotolerant strains and are frequently encountered in hypersaline environments. Within the section Dunaliella are three accepted species, D. salina, D. parva and D. pseudosalina as well as D. bardawil The latter has been debated as to whether it should be deemed to be a separate species, or is D. salina considering its characteristics match the species description originally specified by Teodoresco (1905) (Borowitzka & Siva, 2007; González et al, 2009)

Methods

Results

Conclusion