Biofixation of a high-concentration of carbon dioxide using a deep-sea bacterium: Sulfurovum lithotrophicum 42BKT^T

Concerns about global warming have dramatically increased interest in the development of a strategy for the sustainable and economical fixation of carbon dioxide (CO₂). Achieving treatment of high-concentration CO₂ (e.g., higher than 1 atm CO₂) with a minute thermal energy penalty (e.g., at room temperature) is a significant goal for efficient fixation. Herein, we report the great potential of Sulfurovum lithotrophicum 42BKT^T, a deep-sea sulfur-oxidizing bacterium, for the biofixation of CO₂ at a pressure as high as 2 atm CO₂, mixed with 8 atm N₂, at 29 °C. Sulfurovum lithotrophicum 42BKT^T exhibited a fast specific fixation rate of approximately 0.42 g CO₂ g per cell per h. Moreover, 37% of the total CO₂ fixation was present in the form of five dominant metabolites, especially glutamate and pyroglutamate. This work constitutes an efficient biofixation strategy of high-concentration CO₂ by using a deep-sea chemolithoautotrophic bacterium.