Induction of CO2 and Bicarbonate Transport in the Green Alga Chlorella ellipsoidea (I. Time Course of Induction of the Two Systems)

摘要: Changes in the physiological properties of green alga Chlorella ellipsoidea (UTEX 20) were determined during adaptation from high CO2 to air. Cells C. ellipsoidea, grown CO2, had an extremely low affinity for dissolved inorganic carbon (DIC). However, high-affinity DIC transport was induced rapidly after switching air, which caused a massive decrease concentration medium. Rates O2 evolution without added carbonic anhydrase (CA) compared with calculated rates uncatalyzed formation medium as measure active HCO3-uptake. found be able use HCO3- 5 h and this capacity increased next 17 h. The stimulation upon CA addition used measurement transport: such occurred 2 transfer Increases correlated closely increasing accumulate intracellular pools acid-labile decreases K1/2(CO2) CO2-compensation point cells. Treatment cells cycloheximide (5 [mu]g mL-1) completely inhibited induction, whereas treatment chloramphenicol (400 no effect, indicating requirement cytoplasmic protein synthesis induction. These results suggest that both are air there is temporal separation between induction two systems.