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

大型底栖有孔虫是热带和亚热带环境中重要的碳酸盐生产者，在碳循环中发挥着重要作用。由于气候变化导致海温升高，它们遭受相关硅藻群落的白化。该项目的目的是找出共生硅藻在多大程度上支持全息生物适应更温暖的环境条件（SYMBIOAID）。实验工作的焦点是模式生物双角藻（Amphistegina lobifera），由于其健壮性和体积小，非常适合于培养实验和实验漂白。这个物种可以大量收集，在实验室培养，并用于一些研究共生体的灵活性。薄荷醇漂白后与先前从有孔虫中分离的共生体的再次感染应该显示单个共生体或共生体群落是否会影响有孔虫的耐热性。文献指出，微生物组中的细菌对增强热耐受性的重要性日益增加。对于热暴露实验中有孔虫是否也适用，目前还存在一个知识缺口。方法方法是结合生态生理学实验、显微复制技术和包括硅藻和细菌在内的共生体群落的分子分析。通过这种方法，SYMBIOAID将有助于更好地理解共生生物的灵活性，揭示其对气候变化的生理适应能力。

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.