The dissolution of CO2, a greenhouse gas most responsible for global warming, in seawater lowers its pH and increases its ionic strength. Sulfurovum lithotrophicum 42BKTT, a deep-sea chemolithotrophic bacterium, can fix high concentration CO2. In this study, we investigated the effect of pH and ionic strength variation of seawater on CO2 fixation by this bacterium. For a stable and continuous fixation of high concentration CO2 by S. lithotrophicum 42BKTT, the pH and ionic strength of the seawater-based medium should be 6.1–6.8 and <0.8 M, respectively. The deviation of pH and ionic strength from these ranges was indicated by the appearance of lengthened and fattened cells whose length and diameter increased by 70–90%. These results imply that the harmful effect of dissolved CO2 on marine ecosystem is due to the increase in ionic strength and decrease in pH of seawater.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)