SYMBIOAID: The role of diatom endosymbionts on the adaptive potential of benthic foraminifera to climate change

• Applicant: Dr. Christiane Schmidt, Ph.D.
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Palaeontology
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444059848

Larger benthic foraminifera are important carbonate producers in tropical and subtropical settings and play a large role in the carbon cycle. They suffer from bleaching of the associated diatom algal community under increased SST due to climate change. The aim of this project is to find out to which extent the symbiotic diatoms support the holobiont to adapt to warmer environmental conditions (SYMBIOAID). In the spotlight of the experimental work is the modell organism Amphistegina lobifera, which is well-suited for cultivation experiments and experimental bleaching because of its robustness and small size. This species can be collected in high numbers, cultured in the laboratory, and used for several investigations of symbiont flexibility. Re-infections after menthol bleaching with previously isolated symbionts from foraminifera should show weather a single symbiont or a symbiont community can influence the thermal tolerance of the foraminifera. The literature points towards an increased importance of bacteria in the microbiome to enhance thermal tolerance. A knowledge gab exists whether this holds true for foraminifera in heat-exposure experiments. The methodological approach are a combination of ecophysiological experiments, microcopy techniques, and molecular analysis of the symbiont communities, which include diatoms and bacteria. With this approach, SYMBIOAID will contribute to better understanding symbiont flexibility and reveal the capacity of physiological adaptation to climate change.

• DFG Programme: Research Grants