The microalga Rhodomonas salina is widely used in aquaculture. There is a need for optimization of the growth of the microalgae and its content of essential fatty acids. Here, the fatty acid profile of Rhodomonas in relation to cell density during cultivation in a tubular PBR is investigated. It is expected that cell density is an important factor in controlling productivity and fatty acid content of the microalgae because cell density is important in determining light availability due to the self‐shading of the algae. The carbon productivity as a function of cell density is described by a saturation curve. The carbon productivity and the productivity of total fatty acids are lowest at the lowest cell density, and independent of cell density at higher cell densities. The relative contribution of the two poly‐unsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increases with increasing cell density and saturates at 1 × 10⁶ cells/ml. We conclude that large‐scale production of Rhodomonas in this tubular PBR should take place at cell densities of 1 × 10⁶ cells/ml, while there are indications for increasing difficulties in maintaining steady‐state production in this PBR at higher cell densities.

中文翻译：

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管状光生物反应器培养红景天过程中细胞密度对生物量和脂肪酸生产力的影响

微藻红景天盐沼被广泛用于水产养殖。需要优化微藻的生长及其必需脂肪酸的含量。在这里，红景天的脂肪酸特征研究了在管状PBR中培养过程中细胞密度的相关性。预计细胞密度是控制微藻产量和脂肪酸含量的重要因素，因为由于藻类的自遮蔽性，细胞密度对于确定光的利用率很重要。碳生产率作为细胞密度的函数由饱和曲线描述。碳生产率和总脂肪酸生产率在最低细胞密度下最低，而在较高细胞密度下与细胞密度无关。两种多不饱和脂肪酸二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的相对贡献随着细胞密度的增加而增加，并以1×10 ⁶细胞/ ml饱和。我们得出结论，大规模生产Rhodomonas在该管状PBR应当在1×10细胞密度⁶个细胞/ ml，而存在用于在维持稳态生产中此PBR在更高的细胞密度越来越多的困难指示。