The effect of acetate on the oxygen production of <i>Chlamydomonas reinhardtii</i>


  • Daniela Castillo
  • Ivy Chang
  • Jenny Kim
  • Monica Ng


Chlamydomonas reinhardtii is a unicellular green alga used for studying the processes of photosynthesis. C. reinhardtii can fix many forms of carbon, including acetate. The effect of acetate on the oxygen production of the wild type strain CC-1690 - wild type mt+ 21 gr was observed by measuring oxygen levels in culture media containing four different concentrations of sodium acetate: 0mM, 10mM, 20mM, and 30mM. The four treatments were exposed to a light intensity of approximately 2550 lux at 25oC for 1 hour. Differences in initial and final oxygen concentrations and cell densities were measured for three replicates of each treatment. The 0mM medium was found to have the largest oxygen production at 5.6×10⁻⁶± 7.8×10⁻⁷ mg/L/cell, while the 10mM, 20mM, and 30mM treatments were found to have similar oxygen productions at 2.66×10⁻⁶± 6.37×10⁻⁷, 2.70×10⁻⁶± 6.91×10⁻⁷, and 3.30×10⁻⁶± 4.99×10⁻⁷ mg/L/cell respectively. A p-value of 2.1× was calculated through an analysis of variance and showed a statistical difference in the means of the four treatments. It is suspected that as C. reinhardtii used acetate as a carbon source instead of carbon dioxide, the photosynthetic rates in the treatments containing acetate were lowered, resulting in decreased oxygen production levels. We were able to conclude that the presence of acetate has an effect on the oxygen production of C. reinhardtii.