Enhancing molecular traits of green microalgae: developing Chlamydomonas reinhardtii and Chlorella vulgaris for industrial applications

Microalgae are gaining attention as sustainable biotechnological platforms due to their ability to produce valuable compounds relevant to fuels, nutrition, medicine, and environmental applications. This thesis focuses on two green microalgae: Chlamydomonas reinhardtii, which is easy to work with in the lab but not ideal for industrial use, and Chlorella vulgaris, which grows fast and is already used in products like supplements, though it's harder to genetically modify. In detail, the first part is focused on the successful engineering of C. reinhardtii to produce polycyclopropanated fatty acids—energy-dense compounds suitable as sustainable rocket fuels—demonstrating how microalgae can contribute to next-generation bioenergy solutions. The second and third parts involved random mutagenesis applied on Chlorella vulgaris to soften the cell wall, making it easier to get valuable compounds out of it and improve the pigments in C. vulgaris so it looks and tastes better in food products like crackers. Finally, the thesis explores using algae as little bio-factories to produce plant-friendly peptides to help crops grow better, especially under stress. Together, these projects reveal the vast untapped potential of green algae in sustainable industries. They also highlight the technical hurdles that must be addressed—especially in genetic accessibility and metabolic optimization—to bring algal biotechnology from lab-scale concepts to widespread industrial implementation. Through its multifaceted approach, the thesis lays a foundation for a future where microalgae contribute meaningfully to energy, health, and agriculture in a circular, bio-based economy.