A terrestrial green alga was isolated at Iceland, and the strain (SAG 2627) was described for its morphology and phylogenetic position and tested for biotechnological capabilities. Cells had a distinctly curved, crescent shape with conical poles and a single parietal chloroplast. Phylogenetic analyses of 18S rDNA and rbcL markers placed the strain into the Trebouxiophyceae (Chlorophyta). The alga turned out to belong to an independent lineage without an obvious sister group within the Trebouxiophyceae. Based on morphological and phylogenetic data, the strain was described as a new genus and species, Thorsmoerkia curvula gen. et sp. nov. Biomass was generated in column reactors and subsequently screened for promising metabolites. Growth was optimized by pH-regulated, episodic CO2 supplement during the logarithmic growth-phase, and half of the biomass was thereafter exposed to nitrogen and phosphate depletion. The biomass yield reached up to 53.5 mg L-1 day-1. Fatty acid (FA) production peaked at 24 mg L-1 day-1 and up to 83% of all FAs were unsaturated. At the end of the log phase, approximately 45% of dry mass were lipids, including eicosapentaenoic acid. Carotenoid production reached up to 2.94 mg L-1 day-1 but it was halted during the stress phase. The N-linked glycans of glycoproteins were assessed to reveal chemotaxonomic patterns. The study demonstrated that new microalgae can be found at Iceland, potentially suitable for applied purposes. The advantage of T. curvula is its robustness and that significant amounts of lipids are already accumulated during log phase, making a subsequent stress exposure dispensable.

• Keywords
• Biodiversity, Iceland, Polyunsaturated fatty acids, Semi-terrestrial algae, Taxonomy, Trebouxiophyceae,
• Publication type
• Journal Article MeSH

A terrestrial green microalga was isolated at Ås, in Akershus County, Norway. The strain corresponded to a coccoid chlorophyte. Morphological characteristics by light and electron microscopy, in conjunction with DNA amplification and sequencing of the 18 s rDNA gene and ITS sequences, were used to identify the microalgae. The characteristics agree with those of the genus Coelastrella defined by Chodat, and formed a sister group with the recently described C. thermophila var. globulina. Coelastrella is a relatively small numbered genus that has not been observed in continental Norway before; there are no previous cultures available in collections of Norwegian strains. Gas chromatography analyses of the FAME-derivatives showed a high percentage of polyunsaturated fatty acids (44-45%) especially linolenic acid (C18:3n3; 30-34%). After the stationary phase, the cultures were able to accumulate several carotenoids as neoxanthin, pheophytin a, astaxanthin, canthaxanthin, lutein, and violaxanthin. Due to the scarcity of visual characters suitable for diagnostic purposes and the lack of DNA sequence information, there is a high possibility that species of this genus have been neglected in local environmental studies, even though it showed interesting properties for algal biotechnology.

• Keywords
• 18S rDNA, Algae phylogeny, Electron microscopy, Fatty acids, ITS, Strain FGS-001,
• MeSH
• Pigments, Biological analysis   MeSH
• Biotechnology MeSH
• Chlorophyta classification   cytology   genetics   MeSH
• Species Specificity MeSH
• Pheophytins analysis   MeSH
• Phylogeny * MeSH
• Carotenoids analysis   MeSH
• alpha-Linolenic Acid analysis   MeSH
• Fatty Acids analysis   MeSH
• Microalgae classification   cytology   genetics   isolation & purification   MeSH
• DNA, Ribosomal MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• Xanthophylls MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Norway MeSH
• Names of Substances
• astaxanthine MeSH Browser
• Pigments, Biological MeSH
• Pheophytins MeSH
• Carotenoids MeSH
• alpha-Linolenic Acid MeSH
• Fatty Acids MeSH
• neoxanthin MeSH Browser
• DNA, Ribosomal MeSH
• RNA, Ribosomal, 18S MeSH
• violaxanthin MeSH Browser
• Xanthophylls MeSH