Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia E Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
REQUIMTE/LAQV, Instituto Superior de Engenharia, Instituto Politécnico Do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072, Porto, Portugal.
Appl Microbiol Biotechnol. 2022 Jun;106(11):4017-4027. doi: 10.1007/s00253-022-11968-1. Epub 2022 May 23.
Two environmental parameters, temperature and light intensity, were independently used as stress modulators to enhance eicosapentaenoic acid (EPA) production by the microalga Nannochloropsis oculata, without hindering biomass production. A sinusoidal approach was used, as environmental conditions were alternated between optimum and stress status in multi-day cycles. Low temperatures (5 and 10 °C) and light intensities (30 and 50 μmol photons/m/s) were tested. Results revealed that the modulated stress approach used was able to avoid decreases in biomass production. Temperature stress (10 °C) presented the highest impact, increasing EPA content to 12.8 mg/L, 158% more than the amount obtained in optimum (non-modulated) growth conditions at that point in time, while the lower light intensity stress was able to increase to 126% more. It is important to point out that in both cases increases in EPA amounts resulted from increased content in each individual cell and not just from increased biomass contents. KEY POINTS: • Temperature stress (10 °C) presented the highest impact increasing EPA content 158% • Lower light intensity stress was able to increase EPA to 126% more • EPA increased in individual cell contents simultaneous with biomass increase.
两种环境参数，温度和光照强度，被独立用作应激调节剂，以促进微藻眼点拟微绿球藻（Nannochloropsis oculata）的二十碳五烯酸（EPA）生产，而不影响生物量的产生。采用正弦波法，在多日周期内将环境条件在最佳状态和应激状态之间交替。测试了低温（5 和 10°C）和低光照强度（30 和 50 μmol 光子/m/s）。结果表明，所使用的调制应激方法能够避免生物量减少。温度应激（10°C）的影响最大，将 EPA 含量增加到 12.8 mg/L，比当时最佳（非调制）生长条件下的含量增加了 158%，而较低的光照强度应激能够增加 126%。值得注意的是，在这两种情况下，EPA 含量的增加都源于每个细胞中含量的增加，而不仅仅是生物量含量的增加。要点：• 温度应激（10°C）的影响最大，将 EPA 含量增加了 158%• 较低的光照强度应激能够将 EPA 增加 126%• EPA 增加与生物量增加同时发生在单个细胞的含量中。
