Effect of High Temperature on Photosynthetic Electron Transport Activities of the Cyanobacterium Spirulina Platensis

COMBINED EFFECTS OF ULTRAVIOLET RADIATION AND TEMPERATURE ON MORPHOLOGY, PHOTOSYNTHESIS, AND DNA OF ARTHROSPIRA (SPIRULINA) PLATENSIS (CYANOPHYTA)1

“…It is known that temperature affects the ultrastructure (van Eykelenburg 1979), morphology (Mühling et al. 2003), photosynthesis and respiration (Torzillo and Vonshak 1994, Venkataramanaiah et al. 2003), biochemical composition, and growth (Tomaselli et al.…”

“…(2003) reported that an increase in temperature from 30°C to 32°C–34°C for 7 d led to reversed spiral orientation (left‐handed to right‐handed) for three of 10 Arthrospira strains tested. The activity of PSII in A. platensis decreased at high temperature (35°C), while PSI showed an increase in its activity (Venkataramanaiah et al. 2003).…”

“…Mü hling et al (2003) reported that an increase in temperature from 30°C to 32°C-34°C for 7 d led to reversed spiral orientation (left-handed to right-handed) for three of 10 Arthrospira strains tested. The activity of PSII in A. platensis decreased at high temperature (35°C), while PSI showed an increase in its activity (Venkataramanaiah et al 2003). Vonshak (1997) demonstrated that lower temperatures in the morning induced higher photoinhibition under solar radiation, and that heating the culture up to 35°C raised its biomass production.…”

Heat-induced changes in photosystem I activity as measured with different electron donors in isolated spinach thylakoid membranes

“…The same has been shown for intact cells and isolated thylakoids of algae Spirulina pletensis. 26 An increase in the activity of PSI after heat treatment has also been shown to be because of inactivation of SOD. 27, 28 However we believe that if the increase in PSI activity upon heat treatment is because of inhibition of SOD then it should not be different with different donors.…”