Light Em’ Up: How Differing Light Intensities Affect Nannochloropsis oculata Growth

Abstract

Algae is a quickly growing eukaryotic organism that is involved with the production of biofuels. Upon metabolization, algae produces lipids which can then be processed into biofuels. Some of the fuels that are associated with algae production are ethanol and biodiesel (French 2021). The growth rate of algae depends on many factors, the most important being light intensity. Since algae depends on photosynthesis, different light intensities can greatly affect algal growth. In this experiment, we are studying the growth of Nannochloropsis oculata in varying measures of light intensity. After constructing photobioreactors, Nannochloropsis oculata was placed in each of the four bottles. One bottle was left with no covering, while the other three were covered with cheesecloth, mesh, or foil. The cell count, light intensity, and chlorophyll content of each sample were measured. It was hypothesized that a higher light intensity would lead to a higher rate of algal growth because of the increased photosynthesis potential. The results after week 1 were skewed because the oxygen pump was disconnected from the photobioreactor resulting in less oxygen flow. After collecting data during week 2, it was found that covering the photobioreactor in cheese cloth resulted in the highest growth rate out of the 3 experiment groups. The cheesecloth had a chlorophyll content of 3,200 mpl in a 3ml sample and an estimated 2650 cells per μL, compared to our control that had a chlorophyll content of 855.2 mpl and an estimated cell count of 2050μL.