Production potential of eicosapentaenoic acid by the diatom Nitzschia laevis

To investigate the production potential of eicosapentaenoic acid (EPA) by the diatom Nitzschia laevis, the growth characteristics and fatty acid composition of the cells were studied under photoautotrophic, mixotrophic and heterotrophic conditions of growth. The specific growth rate and maximum biomass concentration were respectively 0.466 d−1 and 2.27 g l−1 for mixotrophic culture, 0.344 d−1 and 2.04 g l−1 for heterotrophic culture, and 0.167 d−1 and 0.5 g l−1 for photoautotrophic culture, respectively. As for EPA production, the yield and productivity were respectively 52.32 mg l−1 and 10.46 mg l−1 d for mixotrophic culture, 35.08 mg l−1 and 6.37 mg l−1 d for heterotrophic culture, and 6.78 mg l−1 and 3.39 mg l−1 d for photoautotrophic culture, respectively. Results suggest that mixotrophic culture is the most suitable growth mode for the production of EPA by the diatom Nitzschia laevis. The results are useful for the development of a cost-effective fermentation process for EPA production by Nitzschia laevis.