<i>Tetraedron minimum</i>, First Reported Member of Hydrodictyaceae to Accumulate Secondary Carotenoids
Philipp Doppler,
Christoph Kornpointner,
Heidi Halbwirth,
Daniel Remias,
Oliver Spadiut
Affiliations
Philipp Doppler
Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
Christoph Kornpointner
Research Division Phytochemistry and Plant Biochemistry, Institute of Chemical, Environmental, and Bioscience Engineering, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
Heidi Halbwirth
Research Division Phytochemistry and Plant Biochemistry, Institute of Chemical, Environmental, and Bioscience Engineering, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
Daniel Remias
School of Engineering, University of Applied Sciences Upper Austria, Stelzhamerstr. 23, 4600 Wels, Austria
Oliver Spadiut
Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
We isolated a novel strain of the microalga Tetraedron minimum in Iceland from a terrestrial habitat. During long-term cultivation, a dish culture turned orange, indicating the presence of secondary pigments. Thus, we characterized T. minimum for growth and possible carotenoid production in different inorganic media. In a lab-scale photobioreactor, we confirmed that nitrogen starvation in combination with salt stress triggered a secondary carotenoid accumulation. The development of the pigment composition and the antioxidant capacity of the extracts was analyzed throughout the cultivations. The final secondary carotenoid composition was, on average, 61.1% astaxanthin and 38.9% adonixanthin. Moreover, the cells accumulated approx. 83.1% unsaturated fatty acids. This work presents the first report of the formation of secondary carotenoids within the family Hydrodictyaceae (Sphaeropleales, Chlorophyta).
