The effect of increasing light intensity on oxygen production in <i>Chlamydomonas reinhardtii</i>

Abstract

The single-celled green alga, Chlamydomonas reinhardtii, is a commonly used model organism, especially in studies involving photosynthesis. Our study focuses on the effects of varying light intensities on oxygen production by C. reinhardtii. There were four replicates of wild-type C. reinhardtii per light intensity treatment (480, 1000, 3160, and 5150 lux). Each one was exposed to its treatment for 1.5 hours and oxygen concentrations were measured before and after each treatment. Overall, we observed an increasing rate of oxygen production with increasing light intensity. A one-way ANOVA test resulted in a p-value of 0.0248. It is likely the significant differences arise between the 480 lux and 3160 lux treatment and between the 480 lux and 5150 lux treatment since the 95% confidence intervals of the means for oxygen production at these light intensities do not overlap.  Increasing light causes an increase in the photosynthetic rate most likely due to light’s stimulatory effect on Photosystem II of C. reinhardtii.