Application study for the high CO2 tolerant Chlorella strain by flue gas culture: Evaluation of growth performance and adaptive mechanisms

Abstract

The application of microalgae for CO2 biosequestration of flue gas emissions from coal-fired power plants has attracted widespread attention. In this study, one high CO2 tolerant Chlorella strain (LAMB 31) screened by previous experiments was cultured with flue gas of a power plant, whose multiple growth performance and the adaptive mechanisms under the flue gas were investigated. The results indicated LAMB 31 grew well under the flue gas with a specific growth rate of 0.15/d and a maximum carbon fixation rate of 0.24 g/L/d. Correspondingly, LAMB 31 increased intracellular chlorophyll and fatty acid content (especially unsaturated fatty acids), while relatively low intracellular arsenic and mercury were accumulated, showing advantages of LAMB 31 for further food/feed and biodiesel production. Transcriptional results showed that enhancing carbon turnover and storage processes were the major mechanism for LAMB 31 adapting flue gas culture. Furthermore, inhibited uptake and enhanced detoxification of heavy mental were also found, verifying that LAMB 31 could effectively control the intracellular heavy mental accumulations. This study comprehensively evaluated the growth performance, elucidated possible adaptive strategies of Chlorella sp. responding to the flue gas, and provided further directions for the subsequent applications of LAMB 31 biomass.