ABSTRACT Microalgae are important producers in aquatic ecosystems and are valuable for biodiesel production and feed supply industries. Three such microalgae, Nannochloropsis oceanica (Eustigmatophyceae), Dunaliella salina (Chlorophyceae), and Chlamydomonas reinhardtii (Chlorophyceae), were cultured at two pCO2 (400 ppm, 1000 ppm) to investigate changes in fatty acid and amino acid composition. Elevated pCO2 increased C16:0, C18:3, C20:5, total saturated fatty acid (SFA), total polyunsaturated fatty acid (PUFA), and total essential amino acid (EAA) content in N. oceanica. High CO2 concentration reduced C16:0 and total SFA content, but increased C18:3, total PUFA, and total EAA accumulation, in D. salina. Changes in C. reinhardtii were the opposite of those in D. salina. Results indicated that higher pCO2 may improve the quality of biodiesel produced by N. oceanica and C. reinhardtii. Furthermore, in N. oceanica and D. salina, increased CO2 concentration elevated nutrient levels but resulted in reduced nutrient quality in C. reinhardtii. Our results can help predict nutritional changes in microalgae at elevated pCO2, and provide insight into production of biodiesel and animal feed by microalgae.

中文翻译：

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CO2浓度升高对三种微藻脂肪酸和氨基酸变化的影响

摘要 微藻是水生生态系统中的重要生产者，对生物柴油生产和饲料供应行业很有价值。在 2 pCO2（400 ppm、1000 ppm）下培养三种微藻，即大洋藻纲（Eustigmatophyceae）、盐生杜氏藻（绿藻科）和莱茵衣藻（绿藻科），以研究脂肪酸和氨基酸组成的变化。升高的 pCO2 增加了大洋菜中 C16:0、C18:3、C20:5、总饱和脂肪酸 (SFA)、总多不饱和脂肪酸 (PUFA) 和总必需氨基酸 (EAA) 的含量。在 D. salina 中，高 CO2 浓度降低了 C16:0 和总 SFA 含量，但增加了 C18:3、总 PUFA 和总 EAA 积累。C. reinhardtii 的变化与 D. salina 的变化相反。结果表明，较高的 pCO2 可能会提高 N. Oceanica 和 C. reinhardtii 生产的生物柴油的质量。此外，在 N. Oceanica 和 D. salina 中，CO2 浓度增加会提高养分水平，但导致莱茵衣藻的养分质量降低。我们的结果可以帮助预测 pCO2 升高时微藻的营养变化，并提供对微藻生产生物柴油和动物饲料的见解。