Cindy Tsou and Lindsay Shiroma, sophomores at Mililani High School, won top honors at the Central District Science Fair held at Honolulu Community College this year. In May 2017, they will present their project entitled, “The Effect of Nutrient Limitation on Algal Biomass Production” at the International Science and Engineering Fair in Los Angeles. These students designed a photo-bioreactor system that provided algae with carbon dioxide, oxygen and aquarium growth lights for an optimal growth environment for the algae. It’s no wonder that these young women placed first when you consider that their research is normally too complex to conduct for a science fair project. As Lindsay tells it
Some of the questions we researched were what nutrients we should use and what concentrations we should use, what kind of algae should we conduct this experiment on, what steps should we take for the analysis, and how could our project help the earth.
Cindy and Lindsay came up with this idea when they realized how dependent our society was on harmful fossil fuels. In their exploratory research, the students identified algae biofuels as the best source of renewable energy because it was environmentally sustainable, easy to cultivate, and growable in salt water and waste water locales. They used different concentrations for each nutrient studied and performed three different trials.
The team admitted encountering problems in constructing the photo-bioreactor and managing the algae analysis process. They indicated that the most difficult part was doing the algae analysis. They had 39 different bottles to perform the analysis on. The process was arduous:
We had to prepare it by putting the algae in test tubes, put them through the centrifuge, then we had to put in a phosphate buffer and centrifuge it again about three times. Doing this to all 39 bottles took about two months since we had limited access to the school lab. Next, we decided to do hexane extraction to remove the lipids from the algae and get the pure biomass content. Handling the hexane was difficult since it is not safe for your body and it evaporates very quickly. Luckily, preparing the algae with the hexane only took a day, but it took another two days to extract the lipids from the algae.
Both students appreciated the guidance and mentoring provided by Mililani teachers Namthip Sitachitta and Christopher Johnson. Cindy said, “They gave us lots of helpful advice that encouraged us to continue improving and working hard.” Lindsay added that Ms Sitachitta, who teaches pre-AP Chemistry and AP Chemistry, “helped us all the way” starting with the procedures to follow and understanding the purpose for each step. Cindy and Lindsay also acknowledged their parents, who helped set up the photo bioreactor and “drove us around.” Lindsay’s mother, who had experience judging state science fairs for biology, assisted them with their project board. The project made both students realize the potential of algae in contributing to a better and cleaner environment.