Investigating the effect of Magnesium on the Oxygen Production of Euglena Gracilis cells.

  • Rasheed Abuarja
  • Hakha Behmanesh
  • Riley Cox
  • Juan Gomez


This experiment aims to shed more light on the correlation between different levels of magnesium ions and oxygen production (photosynthetic rates) of Euglena gracilis. This is of particular relevance with regards to salmon ecosystems, since an increased productivity of Euglena, which form the base of the freshwater salmon food web, could result in an increased oxygen level and abundance of prey, both of which are vital for salmon growth and development. There were three different magnesium levels, 0.049 mg/mL, 0.02 mg/mL and 0 mg/mL (control). Five replicates for each magnesium level were incubated for 18 hours under a light-only cycle to allow for maximum photosynthetic activity. The initial value and final values were measured and recorded for both oxygen concentration and cell count, which allowed us to find the change in oxygen production per cell for each magnesium treatment. Following this, the mean change in oxygen production per cell (n=5) was calculated per treatment, as well as a oneway ANOVA with a Tukey-Kramer test. The ANOVA showed significant differences in the means of the groups (P=0.0016), and the Tukey-Kramer test showed that the 0.049 mg/mL treatment found to be significantly different than both the 0.02 (P=0.0015) and the 0 mg/mL treatment (P= 0.0145). Whereas the 0.02 mg/mL and the 0 mg/mL were not statistically different from each other (P=0.4341). The change in oxygen production was found to be negative in all three treatments due to an inadequate light intensity which resulted in a photosynthetic rate that was less than the cellular respiration rate. Despite this, the 0.049 mg/mL experienced the smallest decrease in oxygen which could indicate that the cells experienced a higher photosynthetic rate, allowing them to better counteract the loss of oxygen from cellular respiration. Given the significant differences between the highest magnesium group and the other two groups, we were able to reject the null hypothesis in favour of our alternate hypothesis, which states that magnesium levels will affect oxygen production in E. gracilis cells.