NSF-BSF: The role of rhodopsin phototrophy in ocean's solar energy capture and its regulation in contrasting nutrient regimes

NSF-BSF：视紫红质光养在海洋太阳能捕获中的作用及其在对比营养状况中的调节

• 批准号: 1924464
• 负责人: Laura Gomez-Consarnau
• 金额: $ 65.49万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924464&HistoricalAwards=false
• 关键词: NSF; BSF; role; rhodopsin; phototrophy

This is a project jointly funded by the National Science Foundation's Directorate of Geosciences (NSF-GEO) and the Israel Binational Science Foundation (BSF) in accord with the language in the Memorandum of Understanding between the NSF and the BSF. This Agreement allows a single collaborative proposal, involving US and Israeli investigators, to be submitted and peer-reviewed by NSF. Upon successful results of the NSF merit review and recommendation by the cognizant NSF Program of an award, each Agency funds the proportion of the budget and the investigators associated with its own country. Rhodopsin phototrophy is the simplest light-dependent metabolism in nature. Since its discovery in marine systems over two decades ago, rhodopsin genes have been found in most microorganisms of the surface ocean. This implies that some of the solar energy that reaches the ocean could be channeled by metabolisms other than conventional chlorophyll-based photosynthesis. Despite the potential importance of rhodopsin phototrophy in marine energy fluxes and the global carbon cycle, its ecological role remains elusive. To study its relevance, this team has developed an analytical method to determine the concentrations of the light-sensitive pigment in rhodopsins, the chromophore retinal. First estimates suggest that rhodopsins are able to capture more sunlight energy than chlorophylls in marine regions where inorganic nutrients are very low, such as the Mediterranean Sea. Yet, these patterns seem to be opposite in the coastal north Pacific Ocean where high rhodopsin synthesis also occurs during the high-nutrient upwelling season. Therefore, it is still unclear which environmental variables are driving rhodopsin synthesis in the ocean. The overall goal of this project is to understand the effects of nutrient availability on marine rhodopsin production and light utilization in systems representative of vast areas of the world ocean. These data are key to further extrapolate the role of rhodopsins at a global scale and to predict their impact on ocean dynamics under different climate change scenarios. Broader impacts of this project include supporting the dissertation work of two graduate students and the active participation of undergraduate and underrepresented minority high school students in fieldwork and laboratory experiments.This project studies the effects of nutrient availability on microbial rhodopsin phototrophy in two marine regions which are representative of large areas of the world ocean: the oligotrophic P-limited Eastern Mediterranean Sea and the upwelling N-limited North Pacific. Monthly In situ rhodopsin quantifications coupled with metagenomics and metatranscriptomics are being used to identify the seasonal patterns of rhodopsin- based phototrophy in different microbial taxonomic groups and environments. These field data are complemented with seawater nutrient enrichment incubation experiments, which links nutrient availability to rhodopsin-mediated light capture in a controlled setting. Finally, studying the particular physiology of rhodopsin-containing bacteria isolated from the North Pacific coast and the Eastern Mediterranean allows the synthesis regulation strategies used by bacteria from different marine regions and lifestyles to be determined. Overall, this combination of observational and manipulative approaches will provide a more complete and comprehensive understanding of the effect of nutrient supply on rhodopsin distribution, synthesis regulation and energetic gain. The scientific and societal impacts of this project include understanding the consequences of a potential expansion of rhodopsin phototrophy in response to climate change forcing.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.

这是一个由国家科学基金会地球科学理事会（NSF-GEO）和以色列两国科学基金会（BSF）共同资助的项目，符合NSF和BSF之间谅解备忘录中的语言雅阁。该协议允许一个单一的合作建议，涉及美国和以色列的调查人员，提交和同行评审的NSF。一旦NSF的优点审查结果成功，并由认可的NSF计划推荐一个奖项，每个机构资助的预算和与自己的国家相关的调查员的比例。 视紫红质光养是自然界中最简单的光依赖性代谢。自20多年前在海洋系统中发现视紫红质基因以来，已在大多数海洋表层微生物中发现。这意味着到达海洋的一些太阳能可以通过新陈代谢而不是传统的基于叶绿素的光合作用来引导。尽管视紫红质光养在海洋能量通量和全球碳循环中具有潜在的重要性，但其生态作用仍然难以捉摸。为了研究其相关性，该团队开发了一种分析方法来确定视紫红质中光敏色素的浓度，视紫红质是视网膜的发色团。最初的估计表明，在无机营养物非常低的海洋区域，如地中海，视紫红质能够捕获比叶绿素更多的阳光能量。然而，这些模式似乎是相反的，在沿海的北太平洋，高视紫红质的合成也发生在高营养上升流季节。因此，目前还不清楚是哪些环境变量驱动了海洋中视紫红质的合成。该项目的总体目标是了解世界海洋广大地区代表性系统中营养物质可用性对海洋视紫红质生产和光利用的影响。这些数据对于进一步推断视紫红质在全球范围内的作用以及预测其在不同气候变化情景下对海洋动力学的影响至关重要。该项目的更广泛影响包括支持两名研究生的论文工作，以及本科生和代表性不足的少数民族高中生积极参与实地考察和实验室实验，该项目研究了营养物质可利用性对两个海洋区域微生物视紫红质光养作用的影响，这两个海洋区域代表了世界海洋的大片区域：贫营养的P有限的东地中海和上升流的N有限的北太平洋。每月原位视紫红质定量与宏基因组学和元转录组学相结合，用于确定不同微生物分类组和环境中基于视紫红质的光养的季节模式。这些现场数据与海水营养物富集培养实验相补充，该实验将营养物的可用性与受控环境中的视紫红质介导的光捕获联系起来。最后，研究从北太平洋沿岸和东地中海分离的含视紫红质细菌的特定生理学，可以确定来自不同海洋区域和生活方式的细菌所使用的合成调节策略。总的来说，这种观察和操作方法的结合将提供一个更完整和全面的了解营养供应对视紫红质分布，合成调节和能量增益的影响。该项目的科学和社会影响包括理解视紫红质光养作用在应对气候变化强迫方面的潜在扩张的后果。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。

项目成果

Microbial rhodopsins are increasingly favoured over chlorophyll in High Nutrient Low Chlorophyll waters

• DOI: 10.1111/1758-2229.12948
• 发表时间: 2021-04-18
• 期刊: ENVIRONMENTAL MICROBIOLOGY REPORTS
• 影响因子: 3.3
• 作者: Hassanzadeh, Babak;Thomson, Blair;Gomez-Consarnau, Laura
• 通讯作者: Gomez-Consarnau, Laura

Environmental gradients and physical barriers drive the basin‐wide spatial structuring of Mediterranean Sea and adjacent eastern Atlantic Ocean prokaryotic communities

• DOI: 10.1002/lno.11944
• 发表时间: 2021-10
• 期刊: Limnology and Oceanography
• 影响因子: 4.5
• 作者: M. Sebastián;E. Ortega‐Retuerta;Laura Gómez-Consarnau;M. Zamanillo;M. Álvarez;J. Arístegui;J. Gasol