Collaborative Research: Ecology and Evolution of Microbial Interactions in a Changing Ocean

化石燃料释放的二氧化碳正在导致海洋变得更加酸性。人们一直在关注这将如何影响珊瑚等有壳动物，但酸化也会影响构成海洋食物链基础的藻类。未来的藻类群落可能会与今天大不相同，对渔业、娱乐和气候产生潜在的负面影响。或者，这些藻类可能能够迅速适应，以避免最坏的情况。这项研究着眼于藻类适应酸化在真实的时间在实验室中，重点是“市场”之间的相互作用藻类和细菌，他们一起生活。研究人员还出海了解实验室实验的适应性是否在现实条件下有益。最终，该项目将帮助科学家更好地了解海洋中最重要和最被忽视的生物将如何应对人类对其栖息地造成的变化。研究人员还利用他们的科学工作创造了从小学到大学的有趣的教育机会，包括琼脂艺术课程，学生们通过用新鲜分离的海洋细菌“绘画”来学习微生物生态学。海洋酸化对钙化生物的影响已经得到了很好的研究，但对pH值变化如何影响浮游植物知之甚少。以前的工作表明，全球丰富的蓝细菌原绿球藻和它的“助手”细菌交替单胞菌之间的互利相互作用在预测的未来二氧化碳条件下破裂，导致原绿球藻的适应性强烈下降。微生物之间的这种种间相互作用可能对许多生态过程都很重要，但由于缺乏对这些相互作用如何演变的了解，因此很难预测它们有多重要。该项目正在使用实验室进化实验来发现进化如何塑造细菌和藻类（如原绿球藻）之间的相互作用，以及这些共同进化的动力学如何影响塑造地球气候的生物地球化学过程。还计划对百慕大大西洋时间序列进行四次研究航行，以研究自然藻类/细菌群落如何对酸化作出反应，以及从实验室实验中进化出来的微生物在暴露于二氧化碳浓度升高的复杂自然群落中是否具有竞争优势。该项目的最终目标是获得对微生物相互作用的机械理解，可用于为地球海洋模型和全球气候的生物反馈提供信息。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Carbon dioxide released from fossil fuels is causing the ocean to become more acidic. Much attention has been given to how this will affect shelled animals like corals, but acidification also affects the algae that form the base of the ocean food chain. It is possible that future algal communities will look very different than they do today, with potentially negative consequences for fisheries, recreation, and climate. Alternatively, it is possible that these algae will be able to adapt rapidly enough to avoid the worst of it. This study looks at algae adapting to acidification in real time in the lab, focusing on "marketplace" interactions between the algae and the bacteria they live alongside. The researchers also go to sea to learn whether adaptations from the lab experiments are beneficial under real-world conditions. Ultimately, this project is helping scientists better understand how the ocean's most important and most overlooked organisms will respond to the changes humans are causing in their habitat. The researchers also use their scientific work to create fun educational opportunities from grade school to college, including agar art classes where students learn about microbial ecology by "painting" with freshly-isolated ocean bacteria.The effect of ocean acidification on calcifying organisms has been well-studied, but less is known about how changing pH will affect phytoplankton. Previous work showed that the mutualistic interaction between the globally abundant cyanobacterium Prochlorococcus and its "helper" bacterium Alteromonas broke down under projected future CO2 conditions, leading to a strong decrease in the fitness of Prochlorococcus. It is possible that such interspecies interactions between microbes are important for many ecological processes, but a lack of understanding of how these interactions evolve makes it difficult to predict how important they are. This project is using laboratory evolution experiments to discover how evolution shapes the interactions between bacteria and algae like Prochlorococcus, and how these co-evolutionary dynamics might influence the biogeochemical processes that shape Earth's climate. Four research cruises to the Bermuda Atlantic Time Series are also planned to study how natural algal/bacterial communities respond to acidification, and whether evolved microbes from laboratory experiments have a competitive advantage in complex, natural communities exposed to elevated CO2. The ultimate goal of this project is to gain a mechanistic understanding of microbial interactions that can be used to inform models of Earth's oceans and biological feedbacks on global climate.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.