Collaborative Research: Assessing the role of compound-specific phosphorus hydrolase transformations in the marine phosphorus cycle

合作研究：评估化合物特异性磷水解酶转化在海洋磷循环中的作用

基本信息

批准号：
1737083
负责人：
Solange Duhamel
金额：
$ 55.61万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2019-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1737083&HistoricalAwards=false
关键词：
Collaborative Research Assessing role compound

项目摘要

Phosphorus (P) is an essential building block for life. Because P is in short supply over vast areas of the ocean, P availability may control biological productivity, such as photosynthesis and carbon fixation, which has implications for uptake of the greenhouse gas carbon dioxide and thus climate regulation. Marine microorganisms must satisfy their nutritional requirement for P by obtaining it from seawater, where P is present in a variety of chemical forms, from simple phosphate ions (Pi) to complex dissolved organic phosphorus (DOP) molecules. The concentration of DOP vastly exceeds Pi over most ocean areas, therefore DOP is a critically important source of P for marine microbial nutrition and productivity. However, much remains unknown about the contribution of specific DOP compounds to the P nutrition, productivity, and structure of marine microbial communities. In this project, the investigators will conduct field experiments in the Atlantic Ocean and perform a series of controlled laboratory studies with pure enzymes and microbial cultures to determine how and to what extent different DOP compounds are degraded to Pi in the marine environment. Furthermore, the contribution of these compound-specific DOP molecules to microbial P nutrition, carbon fixation, and community structure will be determined, thus advancing the current state of knowledge regarding the factors that control the activity and distribution of microbial species in the ocean, and the ocean?s role in the climate system. This project will support two female junior investigators, a postdoctoral researcher, and graduate and undergraduate students. The undergraduate students will be recruited from the Marine Sciences program at Savannah State University, an Historically Black Colleges and Universities. In addition, results will be incorporated into new hands-on K-12 educational tools to teach students about microbial P biogeochemistry, including a digital game and formal lesson plans with hands-on demos. These tools will be validated with K-12 educators and will be widely accessible to the public through various well-known online platforms. These activities will thus reach a broad audience including a significant fraction of underrepresented groups.P is a vital nutrient for life. Marine microorganisms utilize P-hydrolases, such as alkaline phosphatase (AP), to release and acquire phosphate (Pi) from a wide diversity of dissolved organic P (DOP) compounds, including P-esters (P-O-C bonds), phosphonates (P-C), and polyphosphates (P-O-P). Compound-specific DOP transformations have the potential to exert critical and wide-ranging impacts on marine microbial ecology (e.g. variable DOP bioavailability among species), biogeochemistry (e.g. P geologic sequestration via formation of calcium Pi), and global climate (e.g. aerobic production of the greenhouse gas methane by dephosphorylation of methylphosphonate). However, the mechanisms and comparative magnitude of specific DOP transformations, in addition to their relative contributions to microbial community-level P demand, productivity, and structure, are not completely understood. This study will fill these knowledge gaps by tracking the fate of specific DOP pools in the marine environment. Specifically, this project will test four hypotheses in the laboratory using recombinant enzymes and axenic cultures representative of marine eukaryotic and prokaryotic plankton from high and low nutrient environments, and in the field using observational and experimental approaches along natural Pi gradients in the Atlantic Ocean. In particular, the investigators will reveal potential differences in the hydrolysis and utilization of specific DOP compounds at the community- (bulk enzymatic assays), taxon- (cell sorting of radiolabeled cells in natural samples), species- (axenic cultures) and molecular-levels (pure enzyme kinetic studies and cell-associated proteomes and exoproteomes). Results from our proposed work will provide a robust understanding of the enzymatic basis involved in the transformation of specific forms of DOP and create new knowledge on the relative contribution of these specific P sources to Pi production, marine microbial nutrition, community structure, primary productivity, and thus global carbon cycling and climate. In particular, our refined measurements of the concentration of bioavailable DOP and our unique estimates of DOP remineralization fluxes will provide critical new information to improve models of marine primary production and P cycling.

磷（P）是生命的重要组成部分。由于P在海洋广大地区的供应量很短，因此P的可用性可以控制生物生产力，例如光合作用和碳固定，这对吸收温室二氧化碳碳含量和气候调节具有影响。海洋微生物必须通过从海水中获取P的各种化学形式，从简单的磷酸离子（PI）到复杂的溶解有机磷（DOP）分子来满足其对P的营养需求。在大多数海洋地区，DOP的浓度大大超过了PI，因此DOP是海洋微生物营养和生产力的至关重要的P。但是，对于特定DOP化合物对海洋微生物群落的P营养，生产力和结构的贡献，尚不清楚。在该项目中，研究人员将在大西洋进行现场实验，并使用纯酶和微生物培养物进行一系列对照实验室研究，以确定在海洋环境中如何以及在多大程度上将不同的DOP化合物降解为PI。此外，将确定这些化合物特异性DOP分子对微生物P营养，碳固定和社区结构的贡献，从而促进有关控制海洋中微生物活性和分布的因素的当前知识状态，以及海洋在气候系统中的作用。该项目将支持两名女性初级研究人员，博士后研究员以及研究生和本科生。本科生将从历史悠久的黑人学院和大学萨凡纳州立大学的海洋科学课程中招募。此外，结果将纳入新的动手K-12教育工具中，以向学生传授微生物P Biogeochemistry的知识，包括使用动手演示的数字游戏和正式的课程计划。这些工具将通过K-12教育工作者进行验证，并将通过各种知名的在线平台广泛访问公众。因此，这些活动将吸引广泛的受众，包括大量代表性不足的群体。P是生命的重要营养。海洋微生物利用碱性磷酸酶（AP）等P-溶能酶，从广泛的溶解有机P（DOP）化合物中释放和获取磷酸盐（PI），包括P酯（P-O-C键），磷酸盐（P-O-C键），磷酸盐（P-C）（P-C），（P-C），，，，，P-O-C键和多磷酸盐（P-O-P）。复合特异性的DOP转化具有对海洋微生物生态学的关键和广泛影响的潜力（例如，物种之间可变的DOP生物利用度），生物地球化学（例如，通过钙PI的形成）和全球气候（例如通过甲基膦酸盐去磷酸化的温室气甲烷）。但是，除了对微生物社区级别的P需求，生产力和结构的相对贡献外，特定DOP转化的机制和比较幅度尚不完全了解。这项研究将通过跟踪海洋环境中特定DOP池的命运来填补这些知识空白。具体而言，该项目将使用重组酶和轴突培养物在实验室中的四个假设，代表来自高和低营养环境的海洋真核生物和原核生物浮游生物，以及在大西洋海洋天然PI梯度沿线的观察和实验方法中。特别是，研究人员将揭示在社区（大量酶测定），分类群（天然样品中放射性标记细胞的细胞分选），物种（轴突培养物）和分子 - - 分子 - - 分子 - 分类细胞的细胞分选特定DOP化合物的潜在差异。水平（纯酶动力学研究以及与细胞相关的蛋白质组和外蛋白组）。我们拟议的工作的结果将提供对参与DOP的转化涉及的酶基础的强有力理解，并为这些特定P来源对PI生产，海洋微生物营养，社区结构，初级生产力，初级生产力，初级生产率，初级生产率，初级生产率，主要贡献创建新知识。因此，全球碳循环和气候。特别是，我们对生物可用DOP浓度的精致测量以及我们对DOP回忆通量的独特估计将提供关键的新信息，以改善海洋初级生产和P循环的模型。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Preferential utilization of inorganic polyphosphate over other bioavailable phosphorus sources by the model diatoms Thalassiosira spp.

模型硅藻 Thalassiosira spp 优先利用无机多磷酸盐而不是其他生物可利用的磷源。

DOI：
10.1111/1462
发表时间：
2019
期刊：
Environmental Microbiology
影响因子：
5.1
作者：
Diaz, Julia M.;Steffen, Rachel;Sanders, James G.;Tang, Yuanzhi;Duhamel, Solange
通讯作者：
Duhamel, Solange

Phosphorus as an integral component of global marine biogeochemistry