Ozone Inhibition of Photosynthesis in Chlorella sorokiniana.

Exposure of Chlorella sorokiniana (07-11-05) to ozone inhibits photosynthesis. In this study, the effects of ozone on O(2) evolution and fluorescence yields are used to characterize this inhibition. At an ozone dose of about 3 micromoles delivered to 2 x 10(9) cells, the photosynthetic rate of the cells is inhibited 50%, as indicated by a decrease in bicarbonate-stimulated O(2) evolution (control rate, 1.

Ozone-induced Loss of Intracellular Potassium Ion from Chlorella sorokiniana.

The unicellular algae Chlorella sorokiniana was used as a model system to investigate the interaction of ozone with plant cell membranes. Ozone induces K(+) leakage from Chlorella sorokiniana similar to the electrolytic loss observed from many higher plants under stressful conditions. The kinetics of this leakage indicate that ozone initially interacts reversibly (within sec) with sites on membranes allowing a passive efflux of K(+).

Light and calcium interactions in chlorella inhibited by sodium chloride.

Analysis of NaCl toxicity in Chlorella sorokiniana showed decreased growth rates, increased dry weight per cell, increased intracellular Na(+) and Cl(-), more total chlorophyll per cell, a decreased chlorophyll a to chlorophyll b ratio, increased rates of O(2) evolution, and decreased rates of CO(2) fixation when the extracellular concentration of NaCl was increased from zero to 0.3 m. Cultures did not grow at concentrations greater than 0.