Steinrücken Pia, Mjøs Svein A, Prestegard Siv K, Erga Svein R
Department of Biological Sciences, University of Bergen, Bergen, Norway.
Department of Chemistry, University of Bergen, Bergen, Norway.
Front Plant Sci. 2018 Apr 17;9:491. doi: 10.3389/fpls.2018.00491. eCollection 2018.
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 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) than high salinity (0.77 and 0.98 d) cultures.
富含ω-3多不饱和脂肪酸（PUFA）、二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的微藻对于基于微藻的技术有很大需求。先前的实验表明，一种北极硅藻菌株在营养充足的指数生长期和营养耗尽的稳定期，其EPA含量分别从干重的3.0%增加到4.6%。在本研究中，采用析因设计实验，更详细地研究这种效应，并结合不同的盐度和辐照度。一个数学模型表明，生长阶段和盐度单独以及共同作用，都对EPA含量有显著影响。在盐度为22且稳定期5天后，获得了7.1%干重的最大EPA值，这可能与二氧化硅含量降低、含有EPA的储存脂质积累或两者都有关。然而，低盐度（0.54和0.57 d）培养物的生长速率低于高盐度（0.77和0.98 d）培养物。
