Study on high-CO2 tolerant Dunaliella salina and its mechanism via transcriptomic analysis
Bo Huang, Gaopin Qu, Yulong He, Jinli Zhang, Jianhua Fan, Tao Tang
Abstract
Microalgae has been regarded as a promising method for reducing CO 2 emission. High CO 2 concentration generally inhibits algal growth, and previous studies have mostly focused on breeding freshwater algae with high CO 2 tolerance. In this study, one marine algal strain Dunaliella salina ( D. salina ) was grown under 0.03%-30 % CO 2 and 3% NaCl conditions, and was evaluated to determine its potential for CO 2 assimilation. The results showed that D. salina could tolerate 30% CO 2 , and its maximum biomass concentration could reach 1.13 g·L −1 after 8 days incubation, which was 1.85 times higher than that of incubation in air (0.03%). The phenomenon of high-CO 2 tolerance in D. salina culture was discussed basing on transcriptome analysis. The results showed that D. salina was subjected to oxidative stress under 30% CO 2 conditions, and the majority genes involving in antioxidant system, such as SOD, CAT, and APX genes were up-regulated to scavenge ROS. In addition, most of the key enzyme genes related to photosynthesis, carbon fixation and metabolism were up-regulated, which are consistent with the higher physiological and biochemical values for D. salina incubation under 30% CO 2 .