ஐ.எஸ்.எஸ்.என்: 0974-276X
Yue Zhao, Yuyong Hou, Zhiyong Liu, Shulin Chen and Fangjian Chen
Converting CO2 to HCO3- through CO32- as a carbon source for microalgae growth offers an alternative route for CO2 fixation. There, however, are concerns over algae growth inhibition caused by high HCO3- concentration. The exact mechanism of the microalgae response to NaHCO3 stress also needs further understanding. This study evaluated the effect of high HCO3- on enhancing growth of algae Dunaliella salina HTBS by identifying a series of differentially expressed proteins in responding to NaHCO3 stress using iTRAQ (isobaric tags for relative and absolute quantitation) assay. Results showed that HTBS featured with adaptability to broad HCO3- concentrations (25 to 70 g/L NaHCO3). The specific growth rate (OD750) reached 1.08 day−1 at 25 g/L NaHCO3. A total of 196 proteins were observed responsive to 25 g/L NaHCO3 stress. Among these proteins, 84 proteins were up-regulated, whereas 112 down-regulated. Gene Ontology and KEGG pathway analysis showed that most of the up-regulated proteins were involved in transport and respiratory metabolism, and that the majority of the down-regulated proteins accounted for fatty acid oxidative metabolism and photosynthesis. These results provide new insights into the regulation of HCO3- tolerant mechanism in Dunaliella salina HTBS. These findings may be applicable to genetic engineering microalgae for high CO2 fixation efficiency.