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Interactions between phytoplankton and bacterioplankton mediated by volatile organic compounds

挥发性有机化合物介导的浮游植物和浮游细菌之间的相互作用

基本信息

批准号：
1948163
负责人：
Kimberly Halsey
金额：
$ 68.5万
依托单位：
Oregon State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-01 至 2025-02-28
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1948163&HistoricalAwards=false
关键词：
Interactions between phytoplankton bacterioplankton mediated

项目摘要

Communication amongst plants and animals often occurs through molecules that readily evaporate at normal temperatures, called volatile organic compounds (VOCs). Some VOCs that are produced in the ocean and then enter the atmosphere as gases have been seen to play an important role in climate. Since marine microbes both produce and consume these compounds they affect the concentration of VOCs in the surface ocean. The investigators found that as much as 20% of the carbon resulting from photosynthesis leaked out of microscopic plants in the form of VOCs. These molecules were then used by bacteria as a source of carbon and energy. This suggests that VOCs may play a more important role in the flow of carbon in the marine environment than previously thought. This project examines how microscopic plants and bacteria produce and consume different VOCs. It supports professional development training workshops for Oregon high school teachers from rural areas in OSU’s Science & Math Investigative Learning Experiences (SMILE) program. SMILE’s mission is to close the achievement gap for underserved students by increasing their STEM-content knowledge, preparing them to succeed in higher education, and inspiring them to pursue STEM careers. This project also contributes to three workshops per year, training teachers and engaging students with hands-on learning activities on the topic of Carbon Cycling by Marine Microorganisms such as “Clouds in a Bottle”. One graduate student, one post-doctoral scholar, and at least six undergraduate researchers are being trained by participating in research activities. Field observations suggest that volatile organic compounds (VOCs) produced by phytoplankton are either rapidly consumed by bacterioplankton in the surface ocean or emitted into the atmosphere. VOCs are an understudied path for carbon transfer in microbial food webs throughout sunlit marine ecosystems because these compounds require specialized detection methods. Using a new system to study VOCs in suspensions of live plankton cells, 20% of photosynthetic carbon fixation was seen to be transferred as VOCs from a diatom to SAR11 bacterioplankton in co-cultures. Many of these transferred VOC compounds were not known to be growth substrates for bacterioplankton. Both the magnitude and complexity of the observed VOC transfer were surprising. This project extends these observations to a larger set of phytoplankton and bacterioplankton through controlled studies of cultures, co-cultures, and mesocosms. VOC are detected via proton transfer reaction time-of-flight mass spectrometry and isotopic labeling is used to measure the impact of VOC exchange on rates of photosynthesis and bacterial production. VOC production by phytoplankton is measured in response to nutrient-driven variation in growth rates, and over day-night cycles to discern the relationship of VOC production to photosynthetic metabolism and other cellular processes. These experiments enable a better understanding of field observations, in which bacterial consumption of VOCs can appear to significantly outpace production, while temporal variability in VOC production across daily to seasonal scales can cause VOCs to accumulate transiently to pM-nM concentrations in the surface ocean. This project contributes to close the significant gap in knowledge about the range and quantity of VOCs produced by phytoplankton, and about the roles played by these compounds in phytoplankton metabolism.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.

植物和动物之间的交流通常通过在正常温度下容易蒸发的分子发生，称为挥发性有机化合物（VOC）。一些在海洋中产生，然后作为气体进入大气的挥发性有机化合物被认为在气候中发挥着重要作用。由于海洋微生物既产生又消耗这些化合物，它们会影响海洋表面VOCs的浓度。研究人员发现，多达20%的光合作用产生的碳以VOCs的形式从微观植物中泄漏出来。然后这些分子被细菌用作碳和能量的来源。这表明，挥发性有机化合物在海洋环境中的碳流动中可能比以前认为的更重要。该项目研究了微生物和细菌如何产生和消耗不同的VOC。它支持职业发展培训讲习班的俄勒冈州高中教师从农村地区在俄勒冈州立大学的科学数学调查性学习经验（SMILE）计划。SMILE的使命是通过增加他们的STEM内容知识，为他们在高等教育中取得成功做好准备，并激励他们追求STEM职业，来缩小服务不足学生的成就差距。该项目还每年举办三次讲习班，培训教师，并让学生参与“瓶中云”等海洋微生物碳循环专题的实践学习活动。一名研究生、一名博士后学者和至少六名本科生研究员正在通过参加研究活动接受培训。现场观测表明，浮游植物产生的挥发性有机化合物（VOCs）要么被表层海洋中的浮游细菌迅速消耗，要么被排放到大气中。挥发性有机化合物是整个阳光照射的海洋生态系统中微生物食物网中碳转移的一个研究不足的途径，因为这些化合物需要专门的检测方法。使用新系统研究活浮游生物细胞悬浮液中的VOC，发现20%的光合碳固定以VOC形式从共培养物中的硅藻转移到SAR 11浮游细菌中。许多这些转移的VOC化合物是不知道的浮游细菌的生长基质。所观察到的VOC转移的幅度和复杂性都是令人惊讶的。该项目通过对培养物、共培养物和围隔生态系统的受控研究，将这些观测扩展到更大的浮游植物和浮游细菌。VOC通过质子转移反应飞行时间质谱法检测，同位素标记用于测量VOC交换对光合作用和细菌生产速率的影响。浮游植物的挥发性有机化合物生产是根据营养物驱动的生长速率变化来测量的，并在昼夜周期中识别挥发性有机化合物生产与光合代谢和其他细胞过程的关系。这些实验使我们能够更好地了解现场观察，其中细菌消耗VOC的速度可能会显着超过生产，而VOC生产的时间变化在日常到季节尺度可能会导致VOC在海洋表面瞬时积累到pM-nM浓度。该项目有助于填补浮游植物产生的VOCs的范围和数量以及这些化合物在浮游植物代谢中所起作用的知识空白。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而被认为值得支持。