In this study, the effects of five different temperatures and pH conditions on growth and photosynthetic performance of Synechococcus lividus Copeland from Taiwan were monitored in the field and the laboratory by using an underwater pulse-amplitude modulated (Diving-PAM) fluorometer. In the field, the optimal growth temperature of S. lividus was found to be 57°C. Such a finding was congruent with the growth rate in the laboratory culture, in which the optimal growth temperatures ranged from 45 to 60°C. In photosynthetic performance, the light-saturated maximum relative electron transport rate (ETRmax) and the light-limited slope (αETR) exhibited highest values at 50°C. At five different pH conditions, higher ETRmax and αETR were observed from pH 7 to 9. In addition, regression analysis demonstrated a significant positive relationship between the growth rate and the ETRmax values (R2 = 0.9527), indicating that the growth of S. lividus was largely restricted to its photosynthetic performance. In conclusion, the photosynthetic performance and growth of the thermophilic cyanobacterium S. lividus were sensitive to fluctuations in temperature but not in pH. The present investigation offers a better understanding of the photosynthetic physiology.
All Science Journal Classification (ASJC) codes
- Aquatic Science
- Agricultural and Biological Sciences (miscellaneous)
- Plant Science