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Effects of temperature and pH on growth and photosynthesis of the thermophilic cyanobacterium Synechococcus lividus as measured by pulse‐amplitude modulated fluorometry
Author(s) -
Liao ChungChing,
Liu ShaoLun,
Wang WeiLung
Publication year - 2006
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/j.1440-1835.2006.00432.x
Subject(s) - photosynthesis , biology , fluorometer , growth rate , synechococcus , botany , thermophile , cyanobacteria , fluorescence , bacteria , physics , geometry , mathematics , genetics , quantum mechanics
SUMMARY 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 (ETR max ) and the light‐limited slope (α ETR ) exhibited highest values at 50°C. At five different pH conditions, higher ETR max and α ETR were observed from pH 7 to 9. In addition, regression analysis demonstrated a significant positive relationship between the growth rate and the ETR max values ( R 2 = 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.