Biomaterials for controlled release of manganese in zooxanthellae cultures

• Grant number: 24/15890-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Breno Pannia Esposito
• Grantee: Laura Lessinger Checchia
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Coral bleaching is a worrying environmental phenomenon that is directly related to global warming, as rising ocean temperatures disrupt the symbiotic relationship between corals and their associated microalgae, called zooxanthellae. Addressing this environmental crisis is necessarily multifactorial, and one possible strategy is to facilitate the access of the coral-zooxanthellae holobiont to essential nutrients, such as manganese. Manganese is a trace element in the ocean that is essential specifically for zooxanthellae, helping them both by integrating the enzymatic response to oxidative stress caused by rising temperatures and by increasing their photosynthetic efficiency. In order for manganese to reach the corals and cause the positive effect, it is necessary to study different mechanisms for its controlled release, and potential devices are biomaterials based on lignolytic fungi, kefir and kombucha. These three biomaterials will be prepared and impregnated with manganese, and then characterized (structurally and in terms of Mn release profile). Their effects on physiological parameters (growth, chlorophyll production and antioxidant activity) of Symbiodinium microadriaticum, Breviolum minutum and Efrenium voratum, respectively thermosensitive and thermoresistant zooxanthellae species predominant on the Brazilian coast, will be evaluated. These effects will be evaluated at both 25°C and 30°C, representing the ideal situation and that of global warming. Ultimately, it is expected to develop devices for manganese release to benefit zooxanthellae and, consequently, increase the resilience of holobionts to thermal stress conditions.