The combined impact of temperature and light spectra on the fatty acid (FA) composition in microalgae has been sparsely investigated. The aim of this study was to investigate the interactions of light and temperature on the FA composition in Acutodesmus obliquus. For this purpose, A. obliquus was cultivated with different temperatures (20, 30, and 35°C), as well as broad light spectra (blue, green, and red light). Growth and FA composition were monitored daily. Microalgal FA were extracted, and a qualitative characterization was done by gas chromatography coupled with electron impact ionization mass spectrometry (GC-EI/MS). Compared to red light, green and blue light caused a higher percentage of the polyunsaturated fatty acids (PUFA) 16:4, 18:3, and 18:4, at all temperatures. The highest total percentage of these PUFA were observed at the lowest cultivation temperature and blue and green light. These data imply that a combination of lower temperatures and blue-green light (450–550 nm) positively influences the activity of specific FA-desaturases in A. obliquus. Additionally, a lower 16:1 trans/cis ratio was observed upon green and blue light treatment and lower cultivation temperatures. Remarkably, green light treatment resulted in a comparably high growth under all tested conditions. Therefore, a higher content of green light, compared to blue light might additionally lead to a higher biomass concentration. Microalgae cultivation with low temperatures and green light might therefore result in a suitable FA composition for the food industry and a comparably high biomass production.

中文翻译：

---

不同光谱和温度下斜刺棘鱼的生长和脂肪酸组成

温度和光谱对微藻中脂肪酸 (FA) 组成的综合影响研究很少。本研究的目的是研究光和温度对斜刺棘鱼FA 组成的相互作用。为此，A. obliquus在不同温度（20、30 和 35°C）以及宽光谱（蓝色、绿色和红色光）下培养。每天监测生长和 FA 组成。提取微藻 FA，并通过气相色谱结合电子碰撞电离质谱 (GC-EI/MS) 进行定性表征。与红光相比，绿光和蓝光在所有温度下都产生更高百分比的多不饱和脂肪酸 (PUFA) 16:4、18:3 和 18:4。在最低培养温度和蓝光和绿光下观察到这些 PUFA 的最高总百分比。这些数据表明，较低温度和蓝绿光（450-550 nm）的组合对A. obliquus中特定 FA 去饱和酶的活性产生积极影响. 此外，在绿光和蓝光处理以及较低的培养温度下观察到较低的 16:1 反式/顺式比率。值得注意的是，绿光处理在所有测试条件下都导致了相当高的生长。因此，与蓝光相比，更高含量的绿光可能额外导致更高的生物质浓度。因此，低温和绿光下的微藻培养可能会产生适合食品工业的 FA 组合物和相当高的生物质产量。