Page 74 - 《渔业研究》2026年第1期

第 1 期 陈锦莉等： 培养条件对微拟球藻 FACHB-2541 生长和 EPA 合成的影响 71

Influence of culture conditions on growth characteristics and eicosapentaenoic
acid biosynthesis of Nannochloropsis gaditana FACHB-2541

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CHEN Jinli ，XIAO Xuehua ，ZHAO Yixin ，SHI Rui ，ZHOU Youcai ，CHEN Fugang ，HE Yongjin 1,4*
(1. College of Life Sciences, Fujian Normal University, Fuzhou 350117, China;
2. School of Food and Biological Engineering, Fujian Polytechnic Normal University, Fuqing 350300, China;
3. Qingdao Sunrise Health Co. Ltd., Qingdao 266107, China;
4. Engineering Research Center of Industrial Microbiology, Ministry of Education, Fujian Normal University, Fuzhou 350117, China)
Abstract: [Background] Nannochloropsis is a typical oil-producing microalga characterized by rapid growth
and high eicosapentaenoic acid (EPA) content. However, its large-scale application is currently limited by low
biomass yield and insufficient EPA accumulation, highlighting the need to optimize cultivation conditions to
improve productivity. [Objective] This study aims to optimize the cultivation conditions of N. gaditana
FACHB-2541 to enhance its eicosapentaenoic acid (EPA) production, providing theoretical support and technic-
al guidance for its large-scale, high-value applications in aquaculture, food, and pharmaceutical industries.
[Methods] Using f/2 medium as the initial medium, the effects of different nitrogen sources [sodium nitrate
(the control group), urea, ammonium chloride, and ammonium acetate], nitrogen concentrations (50, 100, 150
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and 200 mg/L), and light intensities [75, 150 and 200 µmol/(m ·s)] on the growth, lipid accumulation, and EPA
biosynthesis of N. gaditana FACHB-2541 were investigated. A single-factor experimental design was em-
ployed, and multiple parameters including biomass, lipid content, and EPA yield were evaluated to determine
the optimal cultivation conditions. [Results] The results showed that the set levels of cultivation parameters (ni-
trogen sources, nitrogen concentration and light intensity) had significant effects on the growth performance and
EPA production of N. gaditana FACHB-2541. Among the tested nitrogen sources, ammonium acetate was more
efficiently utilized by N. gaditana FACHB-2541, resulting in faster growth and higher EPA accumulation. At a
concentration of 150 mg/L nitrogen (ammonium acetate), N. gaditana FACHB-2541 achieved the highest bio-
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mass and EPA yield. Moreover, a light intensity of 75 µmol/(m ·s) was more favorable for growth and EPA pro-
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duction compared to higher intensities [150 and 200 µmol/(m ·s)]. Under the optimized conditions (ammoni-
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um acetate as the nitrogen source at 150 mg/L; light intensity [75 µmol/(m ·s)], the microalga exhibited the
maximum biomass of 2.10 g/L and EPA yield of 156.22 mg/L; which were increased by 107.92% and 73.31%
compared to before optimization. [Conclusion] N. gaditana FACHB-2541 under the optimized cultivation con-
ditions was the potential candidate to exploit high-valued EPA production. These studies provide a solid theoret-
ical basis and practical parameters for enhancing the production efficiency of N. gaditana, especially for applic-
ations requiring high-value EPA output. The optimized cultivation strategy proposed here offers operational
simplicity and scalability, making it promising for industrial-scale cultivation in sectors such as aquaculture,
nutraceuticals, and functional food development.
Key words: Nannochloropsis; eicosapentaenoic acid (EPA); growth; nitrogen source; light intensity