Collaborative Research: Vibrio as a model microbe for opportunistic heterotrophic response to Saharan dust deposition events in marine waters

合作研究：弧菌作为模型微生物，对海水中撒哈拉尘埃沉积事件进行机会性异养响应

• 批准号: 1357140
• 负责人: William Landing
• 金额: $ 20.06万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357140&HistoricalAwards=false
• 关键词: Collaborative; Research; Vibrio; model; microbe

Overview: Dust and mineral aerosols are a significant source of micro and macronutrients to oligotrophic ocean surface waters. Evidence is growing that heterotrophic microbes may play key roles in processing deposited minerals and nutrients. Yet it is not known which components of dust stimulate the heterotrophic bacteria, which cellular mechanisms are responsible for the utilization of those components and how the activity of these bacteria affect the availability and utilization of dust-derived minerals and nutrients by marine autotrophs. Knowledge of these factors is key to understanding how dust deposition impacts carbon cycles and for predicting the response of tropical oceans to future changes in the frequency and intensity of dust deposition events. The objective of this project is to examine the specific effects of aeolian dust on heterotrophic microbes in a tropical marine system under controlled conditions. The central hypothesis is that in oligotrophic tropical systems numerically minor opportunistic bacteria are the first responders to influx of dust constituents and respond primarily by rapidly accessing soluble trace metals and limiting nutrients that are deposited with Saharan dust. The project will focus on two specific aims: 1) Quantify changes in community structure, composition and transcriptional activity among marine microbial populations upon exposure to dust, and 2) Identify key components in Saharan dust aerosols that stimulate or repress growth and/or activity in Vibrio, a model opportunistic marine heterotrophic group. The study will use a series of controlled experiments designed to identify and quantify heterotrophic microbial response to dust deposition events using both natural communities and model bacteria (Vibrio) through metagenomics, transcriptomics and atmospheric and marine biogeochemical techniques. This innovative approach will identify the most critical (reactive) components leached from dust aerosols on the microbial community as well as elucidate potential mechanisms of response.Intellectual Merit: There is great interest in the biological response to dust aerosols given its potentially large influence on biogeochemical cycling, but there has been relatively little work that has addressed the mechanisms of response (especially among the heterotrophic microbial fraction) or identified the relative importance of specific constituents of dust aerosols. A detailed framework for microbial response (focusing on opportunistic heterotrophs) will facilitate efforts to link autotrophic and heterotrophic processing. This contribution is significant because it will provide one of the first end-to-end (chemistry to physiology to ecology) mechanistic pathways for marine biological response to desert dust aerosols.Broader Impacts: The outcomes of this research will provide information on an often overlooked component of climate change, the long range effects of desertification, which could impact biogeochemical cycling throughout the oceans. Furthermore, working with Vibrio as a model will have the co-benefit of addressing the possible role of dust deposition on the global rise of a marine infectious agent. Additionally, this project will provide graduate, undergraduate and high school students with both training and active participation in research. All students will have opportunities to present their work at local and regional meetings as well as national (international) conferences. Through on-going programs at each institution, students from STEM under-represented groups will be recruited for research opportunities (and for entry into graduate programs). Additionally, through participation in the Georgia Coastal Research Council results of this work, and related issues in marine science and climate change, will be broadly disseminated to policy-makers and local (coastal) stakeholders through meetings, links to the GRGC website and listserv and targeted publications.

概述：灰尘和矿物气溶胶是寡营养海洋表层水中微量和常量营养素的重要来源。越来越多的证据表明，异养微生物可能在处理沉积的矿物质和营养物质中发挥关键作用。然而，尚不清楚灰尘的哪些成分会刺激异养细菌，哪些细胞机制负责这些成分的利用，以及这些细菌的活动如何影响海洋自养生物对灰尘来源的矿物质和营养物的可用性和利用。了解这些因素对于了解灰尘沉积如何影响碳循环以及预测热带海洋对未来灰尘沉积事件频率和强度变化的响应至关重要。该项目的目的是研究受控条件下风尘对热带海洋系统中异养微生物的具体影响。中心假设是，在贫营养热带系统中，数量较少的机会性细菌是对灰尘成分流入的第一反应者，并且主要通过快速获取可溶性微量金属并限制撒哈拉灰尘沉积的营养物质来做出反应。该项目将重点关注两个具体目标：1）量化暴露于灰尘后海洋微生物种群群落结构、组成和转录活性的变化，2）识别撒哈拉沙尘气溶胶中刺激或抑制生长和/或活动的关键成分。弧菌，一种典型的机会性海洋异养群。该研究将使用一系列受控实验，旨在通过宏基因组学、转录组学以及大气和海洋生物地球化学技术，利用自然群落和模型细菌（弧菌）来识别和量化异养微生物对灰尘沉积事件的反应。这种创新方法将识别微生物群落中从粉尘气溶胶中浸出的最关键（反应性）成分，并阐明潜在的反应机制。 智力优点：鉴于粉尘气溶胶对生物地球化学的潜在巨大影响，人们对粉尘气溶胶的生物反应非常感兴趣。循环，但解决响应机制（尤其是异养微生物部分）或确定粉尘气溶胶特定成分的相对重要性的工作相对较少。微生物反应的详细框架（重点关注机会性异养生物）将有助于将自养和异养处理联系起来。这一贡献意义重大，因为它将为海洋生物对沙漠沙尘气溶胶的反应提供第一个端到端（化学到生理学到生态学）的机制途径之一。 更广泛的影响：这项研究的结果将为经常被忽视的问题提供信息。气候变化的一个组成部分是荒漠化的长期影响，这可能会影响整个海洋的生物地球化学循环。此外，以弧菌为模型进行合作将具有共同的好处，即解决灰尘沉积对海洋传染性病原体全球增长的可能作用。此外，该项目将为研究生、本科生和高中生提供培训和积极参与研究。所有学生将有机会在当地和地区会议以及国家（国际）会议上展示他们的作品。通过每个机构正在进行的项目，来自 STEM 代表性不足群体的学生将被招募以获得研究机会（并进入研究生课程）。此外，通过参与乔治亚州沿海研究委员会，这项工作的成果以及海洋科学和气候变化方面的相关问题将通过会议、GRGC 网站链接和列表服务广泛传播给政策制定者和当地（沿海）利益相关者。有针对性的出版物。