Pick Your Poison: Does Apple juice or Orange juice have a greater effect on Chlorella vulgaris turbidity and pH levels?

Clayton Hedges, Hanah Barker, Tyler Dunn, Denver LaForce


For our study we wanted to find an efficient and safe way to increase the expected growth rate of Chlorella vulgaris (Algae) by measuring its turbidity and pH levels. We understand that algae need carbon dioxide and sunlight to grow and it thrives in environments high in nitrogen, phosphorus, and potassium. In a similar study, it was found that orange juice, which is high in potassium, was able to have a positive effect on the cell growth of algae (Dalgish et al. 2018). The data from this study showed that potassium increases cell growth which led us to test if orange juice or apple juice would have a greater effect on the algae’s overall turbidity of the liquid. Since orange juice is high in potassium and natural sugars, we hypothesize that there will be a higher turbidity and higher liquid density than our control. However, we also tested apple juice, and although it too was high in natural sugars and potassium, we believe that the sodium present would be harmful to growth rate. Based on our findings, we can conclude that orange juice has a higher turbidity and density than our other experimental groups, but the pH levels remained the highest in our control group through the entire experiment. 

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Dalglish, J. Joyner, C. Geist, K. Jackson, and A. Leone. 2018. The OJ Trials: How orange juice affects the growth of Picochlorum oklahomesnse. Journal of Introductory Biology Investigations. 9(2).

French, D. P. 2020. Investigating Biology. A Laboratory Resource Manual. 2020 Edition. Southlake, TX: Fountainhead Press.

Nottingham, M., R. Lively, C. Pugh, T. McGee, and S. Hileman. 2017. Does Algae Have a Sweet Tooth? The Effects of Raw Sugar on Algal Growth. Journal of Introductory Biology Investigations. 6(3).

Schneider, R., A. Sessom, K. Smith, and A. Melton. 2017. We Put the G in Algae: How Gatorade Affects Algae Growth. Journal of Introductory Biology Investigations. 7(2).

Wang C, Li H, Wang Q, Wei P. [Effect of pH on growth and lipid content of Chlorella vulgaris cultured in biogas slurry]. Sheng Wu Gong Cheng Xue Bao. 2010 Aug;26(8):1074-9. Chinese. PMID: 21090111.

Watson, S., H. Wheeler, E. White, J.Williams, and C. Cobbs. 2017. Sugar Sugar, We Got Algae Wanting You:The Effects of Glucose on Algal Growth. Journal of Introductory Biology Investigations. 1(1).


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