The Effects of Coffee Grounds on Cell Growth and Reproduction in Algae in Chlorella sp.

Abstract

Algae requires energy, water, carbon dioxide and a few inorganic nutrients, such as nitrogen and phosphorus, to grow. Coffee grounds (CG) are commonly used as a fertilizer to promote growth due to its 8:1 C:N ratio. This work analyzes the effect of microalgae growth (Chlorella sp.) by using coffee grounds in place of nitrogen (N) and phosphorus (P). Some key questions under investigation include: how do dry coffee grounds (DCG) affect algae growth? Do the concentrations and antioxidants in DCG increase or decrease the growth amount of microalgae? First we created three groups with different amounts of coffee grounds and a separate control group which contained no coffee grounds then replicated the experiment for an additional week.  The results we found were supportive of our hypothesis that DCG increases growth in algae and can be used as a 50:50 fertilizer ratio to increase the rate of photosynthesis.