Project description:Dunaliella salina Bardawil (also known as Dunaliella bardawil) is an extremophilic, unicellular green alga from the Chlorophyte lineage. D. salina is found in hypersaline environments where it can tolerate extremes of heat, light, pH, and up to saturating concentrations of salt. The D. salina Bardawil isolate (UTEX LB 2538) was found in a salt pond near the Bardawil Lagoon on the Sinai peninsula in 1976. This isolate of D. salina is the richest natural source of beta-carotene, a highly valuable commercial product. This accession includes an RNA-Seq analysis of D. salina Bardawil cultures grown in iron-replete (1.5 µM) or iron-deficient (0 µM) media.
Project description:We set out to investigate the genetic adaptions of the known marine fungus Paradendryphiella salina CBS112865 to the degradation of brown macro-algae, expecting to find a repertoire of carbohydrate active enzymes highly specialized to the degradation of algal polysaccharides. We performed whole genome, transcriptome sequencing and shotgun proteomic analysis of the secretome of P. salina growing on three species of brown algae and under carbon starvation. The genome comparison to close terrestrial fungal relatives, revealed P. salina to have a similar, but reduced carbohydrate active enzyme (CAZyme) profile, except for the presence of three putative alginate lyase 7 genes, most likely acquired via ancient horizontal gene transfer event from a marine bacterium and a polysaccharide lyase 8 gene with similarity to ascomycete chondroitin AC lyases. The proteomic analysis revealed both PL7 and PL8 enzymes to be highly abundant in the algal fermentations together with enzymes necessary for degradation of laminarin, cellulose, lipids and peptides. Our findings indicate that the base CAZyme repertoire of saprobic and plant pathogenic ascomycetes with the necessary addition of alginate lyases provide the fungi with the enzymatic capabilities to thrive on brown algae polysaccharides and even cope with the algal defense mechanisms.
