Euglena gracilis Growth Rate Under Different Light Exposure Length and the Underlying Relationship


  • James Campden
  • Harminder Dhillon
  • Tanveer Mahil,
  • Tianjian Qu


In this project, the relationship between the growth rate of Euglena gracilis and the exposure time to light was investigated by developing three experimental groups, collecting the group populations over 12 days and using the values to create a growth curve for each. As light encourages the growth of chlorophyll, we predicted that with longer periods of light exposure, Euglena gracilis culture would grow at a much higher rate compared to the groups that did not receive as much light. The mean growth rate was 0.2004 ± 0.1274 day -1 for 0 hours, 0.3846 ± 0.3426 day -1 for 12 hours, 0.2971 ± 0.3492 day -1 for 24 hours. It was determined that the exposure time to light had no significant effect on the growth rate of Euglena gracilis (p = 0.7570) and suggested that no extensive light source is needed when growing an E. gracilis culture.