Exploring the Impact of Temperature on Micro-algae Growth & their Chemical Composition

"Even the smallest organism can hold the biggest solution."

The Spark

It all started with a mere thought: how can something as minute as algae help solve big environmental problems? Having come across microalgae serving as a source for

biofuels and food supplements several times, I often wondered what features made them so versatile. And during one class discussion on sustainable biotechnology, I had a question about the influence of ambient temperature on growth and composition.

That curiosity started my journey in studying Chlorella vulgaris, among the most effective and adaptive microalgal species. Understanding how temperature affects its nutrients may contribute to explaining possible insights for ecological food and energy production.

Empathy and Observation

The more I researched, the more I realized the sensitivity of microalgae to any

environmental change. From research papers and discussions with experts, I came to

understand that temperature, rather than being a simple growth factor, may redefine their whole chemical makeup.

Some works described how farmers and scientists struggle to provide the optimal growth conditions for large-scale algae production. I have also watched videos from lab cultures showing how cell color and texture modified with different temperatures.

That made me appreciate how sensitive and powerful these microorganisms can be. It was this immense potential toward sustainability that truly motivated me to delve further into temperature as the key variable affecting growth and nutrition.

Research and Design

I had initially intended to test algae growth in the lab directly, but decided to conduct

secondary research owing to resource limitations. My mentor at that time advised me to analyze various experiments that were available along with their published data on Chlorella vulgaris. I compared how temperature changes affected growth rate and the levels of proteins, lipids, and carbohydrates.

Through feedback, I learned to simplify my data charts and focus on trends rather than too many variables. The research gradually evolved into identifying the optimal temperature range for stable growth and nutrient composition. I realized that Chlorella vulgaris grows best between 25°C and 30°C — a range that balances enzyme activity and nutrient synthesis.

The Prototype

My outcome was a detailed analysis model that summarized how temperature affects

Chlorella vulgaris. The results indicated that growth is very slow at 15°C due to a

reduction in metabolic rates,optimal at 25-30°C, while above 32°C growth rates declinefrom heat stress.

Chemically, proteins were reduced under heat, while lipids slightly increased, helping protect the cells. Carbohydrates dropped off at low temperatures due to photosynthesis's efficiency. This should help scientists and eco-farmers find the best

conditions for large-scale production of algae, which can support a sustainable food and biofuel industry.

Reflection: What You Learned

This project taught me how science connects tiny organisms to global challenges. I was taught to critically analyze data from research and felt that usually, scientific progress depends on patience and precision.

Some challenges were simplifying complex information from many different studies into one clear picture, which I overcame by focusing on the consistent data and mentor feedback. I also developed persistence and communication skills while discussing findings and revising my report.

Most importantly, innovation isn't about creating something new, but it's about understanding and improving what already exists. This experience deepened my respect for environmental research, making me more curious about sustainable biology.

The Next Step

This will be followed by an analysis of how the interaction between temperature with light intensity and nutrients influences Chlorella vulgaris growth. I am also interested in working on a small-scale culture experiment in trying out my findings in real conditions.

This project made me want to learn more about bioenergy and environmental

biotechnology. I believe small discoveries-like finding the best temperature for algae-can lead to big steps toward sustainability.

At Keystone International School, students do more than study science, they explore it with purpose. Projects like this reflect our commitment to nurturing curiosity, research skills, and real-world problem-solving from a young age.

If you would like your child to experience a school where curiosity is valued, student research is celebrated, and personalised guidance shapes every learner’s journey, we invite you to explore our programmes.

Blog written by,

Vikas A

Grade 12