Effects of pH Limitation on Population Growth,Nutrient Uptake and Photosynthesis Physiological Processes of Karenia mikimotoi

Abstract:

with the acidification and increased pH caused by the outbreak of red tides in coastal water, the effects of pH on the marine algae physiological and ecological impact have caused human’s concern gradually. In this experiment,the East China Sea common algae- Karenia mikimotoi as research object,different pH effects on the physiological state have been studied. The results showed that pH significantly affect the growth of algae Karenia mikimotoi, nutrient absorption, chlorophyll, photosynthetic rate and affinity for inorganic carbon. When pH = 6.2, the cell growth was inhibited.Growth rate, nutrient absorption, maximum photosynthetic rate and affinity for inorganic carbon are the lowest; When pH = 8.2, the growth of cells ,absorption of nutrients and highest maximum photosynthetic rate are the fastest; pH = 7.2 and 9.2, the algal cells can still maintain higher growth and higher affinity for inorganic carbon is larger than those in pH = 8.2. In short, high or low pH stress can cause adverse changes in the physiological state of the algae Karenia mikimotoi, especially when the pH is too low.