Manganese complexes to increase the resilience of corals and zooxanthellae

• Grant number: 21/14675-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2022
• End date: July 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Breno Pannia Esposito
• Grantee: Beatriz Lage Arcara
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Zooxanthellae, dinoflagellate microalgae of the Symbiodininaceae family, are symbionts of corals and other cnidarians, responsible for most of the energy metabolism of these animals. However, stress episodes such as ocean warming and/or acidification can trigger the disruption of this symbiosis (the "bleaching" of corals), with damage to coral reefs and the entire ecosystem they support. This disruption ultimately negatively affects the fishing and tourism industries in the impacted regions as well. Aiming to help increase the resilience of corals, enriching their environments with essential metals for their vitality, such as manganese, is an interesting strategy. Manganese is a transition metal with a central role in photosynthesis, and as it is a micronutrient that is not very abundant in marine aquatic systems, its levels may contribute to limiting the productivity of the oceans. In this project, Mn complexes (II or III) with the following ligands will be produced and characterized: salicylaldehyde-ethylenediamine (salen), desferrioxamine, citrate and pyrophosphate, in order to favor the absorption of Mn by zooxanthellae and corals. Growth curves for six zooxanthellae clades will be built in collaboration with the Algae Bank of the USP Oceanographic Institute, while the effects of these compounds on the digestive metabolism of hosts will be studied in collaboration with the Enzymology Laboratory and the startup Biofábrica de Corals, from UFPE. (AU)