Image2_Enhancing EPA Content in an Arctic Diatom: A Factorial Design Study to Evaluate Interactive Effects of Growth Factors.pdf

• Main Authors: Pia Steinrücken, Svein A. Mjøs, Siv K. Prestegard, Svein R. Erga
• Format: Still Image
• Language: unknown
• Published: 2018
• Subjects: Botany; Plant Biology; Plant Systematics and Taxonomy; Plant Cell and Molecular Biology; Plant Developmental and Reproductive Biology; Plant Pathology; Plant Physiology; Plant Biology not elsewhere classified; eicosapentaenoic acid (EPA); arctic diatom; factorial design; salinity; growth phase; interactive effects; microalgal biotechnology; Arctic
• Online Access: https://doi.org/10.3389/fpls.2018.00491.s002; https://figshare.com/articles/Image2_Enhancing_EPA_Content_in_an_Arctic_Diatom_A_Factorial_Design_Study_to_Evaluate_Interactive_Effects_of_Growth_Factors_pdf/6147086

Microalgae with a high content of the omega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are of great demand for microalgae-based technologies. An Arctic strain of the diatom Attheya septentrionalis was shown in previous experiments to increase its EPA content from 3.0 to 4.6% of dry weight (DW) in the nutrient-replete exponential phase and nutrient-depleted stationary phase, respectively. In the present study, a factorial-design experiment was used, to investigate this effect in more detail and in combination with varying salinities and irradiances. A mathematical model revealed that both growth phase and salinity, alone and in combination, influenced the EPA content significantly. Maximum EPA values of 7.1% DW were obtained at a salinity of 22 and after 5 days in stationary phase, and might be related to a decreased silica content, an accumulation of storage lipids containing EPA, or both. However, growth rates were lower for low salinity (0.54 and 0.57 d −1 ) than high salinity (0.77 and 0.98 d −1 ) cultures.