Seas and oceans are polluted by a wide range of compounds stemming from human activities. Our team wants to heighten awareness about environmental pollution and particularly its devastating consequences on the aquatic life. In this line of thinking we are driven to design a bioremediation tool based on the considerable filtration capacity of sponges to decrease the marine pollution and protect aquatic ecosystems. We aim at tackling elements of the main pollutant families by focusing on 5 toxic agents: Polychlorinated Biphenyls (PCBs), nitrite, phenol, lead and cadmium.

The PCBs are synthetic organic compounds widely used by industries and found in large quantities in natural environments due to years of intensive use. They are carcinogenic at low-dose through a chronic exposure and particularly bioaccumalable all along the food chain. Likewise, lead and cadmium are bioaccumulable. They can contaminate fishes making them unfit for consumption, causing severe health damages to human who eat regularly these contaminated fishes. Phenol is not recognized as carcinogenic however its toxicity is real, particularly on cardiovascular system and kidneys. It can be found in the environment as a degradation product of pesticides, dyes and polymers. The degradation of fertilizers gives nitrite, another toxic compound for humans, aquatic flora and fauna. The bioremediation tool will be based on Pseudovibrio denitrificans, a bacterium living in symbiosis with Spongia officinalis. Our goal is to engineer the bacterium to detect, signal and degrade/capture pollutants. The project’s originality lies on the duo formed by a bacterial strain (Pseudovibrio denitrificans) and its symbiotic sponge (Spongia officinalis). Combining these two organisms allows for safe containment of the engineered strain while the extensive filtration capacity (20 000 liters of water per day per kg) of the sponge stimulates the optimal sensing, signaling, and capturing of pollutants in water. Subsequently we will bring a new symbiotic chassis in the iGEM competition and an eco-friendly way to decrease the pollutant concentrations underated threshold of toxicity.