Analysis of the coral bleaching phenomenon and exploration of potential Synthetic Biology-based solutions

Coral reefs are among the most diverse and productive ecosystems on Earth, yet they have been under severe anthropogenic threat for decades due to overfishing, pollution, and coastal development. Climate change has further accelerated their decline by introducing two major stressors: ocean acidification and global warming of water temperatures. Among these, the thermal stress is one of the leading causes of coral bleaching, which is a worldwide phenomenon in which the symbiosis between reef-building corals and their endosymbiotic dinoflagellates breaks down. The bleaching phenomenon leads primarily to coral death, but has consequences beyond that, from endangering the whole reef ecosystem biodiversity to economic losses for millions of people who depend on reef ecosystems. This thesis examines the biological and molecular basis of coral bleaching, with a particular focus on the mechanisms of oxidative stress that lead to the collapse of the symbiosis. It then explores emerging approaches to restoration that involve synthetic biology, an interdisciplinary field that combines biology, engineering, and computational sciences to design new genetic systems. Promising strategies include microbiome engineering, genome editing with CRISPR/Cas technology, and the development of synthetic regulatory circuits to enhance coral resilience. While these approaches are still in their early stages of development, they offer scalable and precise tools whose effectiveness could overcome traditional conservation methods. The thesis highlights both the potential and the challenges of applying synthetic biology to reef restoration, underlining the need for further technological development, in particular for genetic toolkits and biosafety measures, and the need for ethical evaluations.