The Effects of Cold Temperature Shock on Chlamydomonas reinhardtii Oxygen Production

Abstract

Chlamydomonas reinhardtii has a photosynthesis process that is multifaceted in its
dependence, as it relies on temperature, carbon dioxide, water, and light exposure. This paper
focuses on the temperature aspect and conducts an experiment where Chlamydomonas reacts to
sudden changes in temperature and examines what kinds of impacts it has on their oxygen levels
and photosynthesis. Nine samples of the stock wewere measured with an oxygen meter to find
their initial oxygen levels, and then equally filled into airtight containers. The samples were
divided into 3 groups, each correlating with a different temperature: 4°, 15°, and 25°C. Each
group was incubated at their corresponding temperature for 60 minutes and was measured again
for final oxygen levels. In addition, the cells of a sample from each group were counted and
compared. The results show that the group placed at 4°C had a significant decrease in oxygen
levels, the group placed at 15°C did not have any noticeable difference, and the group of samples
at 25°C had quite a bit of increase in oxygen. The 25°C group had an average of 115500 cells/ml
while the other two had approximately 176000 cells/ml. However, human error may have
impacted the results as the Chlamydomonas had to be stirred frequently to prevent it from
settling.