The emission of carbon dioxide (CO₂) to the atmosphere at an increasingly high rate is the primary cause of global warming. Previous studies have mostly focused on low CO₂ concentration inputs and the resulting CO₂ concentrating mechanisms (CCM). However, there are relatively few reports on high−CO₂ tolerant species and their tolerance mechanisms. In this study, Scenedesmus sp. was grown under 1–70 % CO₂ conditions, and a transcriptomic analysis was performed to analyze the global gene expression profiles induced by extremely-high CO₂ (70 %) relative to relatively-low CO₂ (1%). Results showed that Scenedesmus sp. produced a maximum biomass of 3.92 g L⁻¹ at 10 % CO₂ and a biomass of 2.75 g L⁻¹ at 70 % CO₂. High relative CO₂ levels (30–70 %) were favorable for accumulation of lipids and yielded a maximum lipid productivity of about 82.9 mg L⁻¹ d⁻¹. The abundance of genes related to oxidoreductase activities and photorespiration were stimulated under 70 % CO₂ condition, which in turn led to overproduction of ROS. In addition, qPCR was used to validate the results from the transcriptomic analysis and found that most genes involving in the antioxidant system, such as CAT and SOD2, were upregulated around 16.5 times under the high CO₂ treatments. In addition, the down-regulation of genes involved in CCM might ensure Scenedesmus sp. rapid adaption to the environmental signal to maintain microalgal growth through energy saving.

二氧化碳（CO ₂）以越来越高的速率排放到大气中是全球变暖的主要原因。先前的研究主要集中在低CO ₂浓度输入以及由此产生的CO ₂浓缩机制（CCM）。但是，关于高CO ₂耐受物种及其耐受机制的报道相对较少。在这项研究中，Scenedesmus sp。在1-70％CO _2的条件下生长该基因，并进行转录组分析以分析由极高的CO ₂（70％）相对较低的CO ₂（1％）诱导的总体基因表达谱。结果表明，景物sp。在10％CO _2下产生的最大生物量为3.92 g L ^-1，在70％CO _2下产生的最大生物量为2.75 g L ^-1。较高的相对CO ₂水平（30–70％）有利于脂质的积累，并产生约82.9 mg L ^-1 d ^-1的最大脂质生产率。在70％CO ₂条件下刺激了与氧化还原酶活性和光呼吸有关的大量基因，进而导致ROS的过量产生。此外，使用qPCR验证了转录组学分析的结果，发现在高CO浓度下，大多数参与抗氧化剂系统的基因，例如CAT和SOD2，均被上调了约16.5倍。_2种治疗。此外，参与CCM的基因的下调可能会确保Scenedesmus sp.。快速适应环境信号，以通过节能来维持微藻生长。