Collaborative Research: Biosignatures of coupled iron and carbon cycling in ferruginous lakes

合作研究：含铁湖泊中铁和碳耦合循环的生物特征

• 批准号: 1660691
• 负责人: Elizabeth Swanner
• 金额: $ 22.79万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660691&HistoricalAwards=false
• 关键词: Collaborative; Research; Biosignatures; coupled; iron

One of the grand challenges of Geobiology is to infer the classes of microbes that shaped the biosphere at the early stages of Earth evolution, and to understand the effects of their activities on the early oceans and atmosphere. The most direct way of addressing this challenge is to use modern environments that can be considered as analogues for those of early Earth. Such analogue environments are rare and valuable. This project will use two lakes in the Midwestern U.S. - Brownie Lake, MN and Canyon Lake, MI - whose waters were recently discovered to harbor abundant dissolved ferrous iron, which makes them good analogues for the anoxic "ferruginous" oceans that persisted for more than 2 billion years of Earth's history (during Archean and Proterozoic eons). Using field and analytical work, these researchers will investigate an early form of photosynthesis that relies on the redox cycling of iron (photoferrotrophy) and the corresponding cycle of methane, which would have been an important part of the ancient carbon cycle. This project will constrain the activity and biosignatures of the involved microorganisms. This is a necessary step to understand the rise of oxygen on Earth, the deposition of extensive iron-rich sediments that represent the majority of modern-day iron ore deposits, as well as major climate perturbations, and enigmatic carbon isotope excursions on the early Earth. A major emerging question is to what extent the greenhouse gas methane was generated and lost to the atmosphere in ferruginous oceans, and how this contributed to the global carbon cycle and climate. As prior investigations of ferruginous lakes as early Earth analogues utilized international sites, this project will serve U.S. scientists by establishing these two national research sites. The project will support two early career researchers, educate two graduate students, and involve several undergraduates in research. Project results and the established study sites will be used in hands-on graduate training in limnology. In collaboration with land managers of the two lakes, the project will provide a detailed physicochemical baseline to inform future water quality monitoring efforts in the lake watersheds, as well as will contribute to the City of Minneapolis environmental education outreach programs.   Photoferrotrophy is thought to have been the major pathway for primary productivity in ferruginous Precambrian oceans. However, current analogues - meromictic ferruginous lakes - either suffer from light limitation for photoferrotrophy, fix carbon through predominantly sulfurbased photosynthetic pathways, or are located in regions unsuitable for seasonal monitoring. Brownie Lake has sufficient light and an abundant community of anoxygenic phototrophs (including photoferrotrophs), and deeper Canyon Lake has an extended oxic-anoxic transition zone and much lower nutrients than Brownie Lake. Together, these lakes comprise a range of conditions to investigate the controls that varying nutrient levels, physiography, and seasonality have on photoferrotrophic primary productivity and methane cycling. The team will monitor aqueous and carbon isotope geochemistry, microbial community composition, and elemental makeup/mineralogy of particulates from the Brownie and Canyon Lake water columns in order to determine: (1) the physicochemical conditions that regulate the presence and activity of photoferrotrophs, (2) the role of resident microbes in iron and carbon cycling, (3) the inorganic and mineral biosignatures that similar microbial communities might have left in Precambrian iron-rich sediments such as Banded Iron Formations (BIF), and (4) the isotopic imprint of photoferrotrophy and methanogenesis/methanotrophy to carbon and iron cycling.

地球生物学的巨大挑战之一是推断在地球进化的早期阶段塑造生物圈的微生物类别，并了解其活动对早期海洋和大气的影响。应对这一挑战的最直接方法是使用可以被视为早期地球人的现代环境。这样的模拟环境很少见。 This project will use two lakes in the Midwestern U.S. - Brownie Lake, MN and Canyon Lake, MI - whose waters were recently discovered to harbor abundant dissolved ferrous iron, which makes them good analogues for the anoxic "ferruginous" oceans that persisted for more than 2 billion years of Earth's history (during Archean and Proterozoic eons).这些研究人员使用现场和分析工作，将研究一种早期的光合作用形式，依赖于铁的氧化还原循环（光含量）和甲烷的相应循环，这本来是古代碳循环的重要组成部分。该项目将限制所涉及的微生物的活性和生物签名。这是了解地球上氧气的兴起的必要步骤，这是代表大多数现代铁矿石沉积物的广泛富含铁的沉积物的沉积，以及主要的气候扰动，以及早期地球上的神秘碳同位素偏移。一个主要的新兴问题是，在多大程度上产生了温室气甲基烯化酶，并在铁质的海洋中丢失了大气，以及这如何促进全球碳循环和气候。作为对铁湖的先前调查，因为地球早期类似物利用了国际地点，该项目将通过建立这两个国家研究地点来为美国科学家提供服务。该项目将支持两名早期的职业研究人员，对两名研究生进行教育，并涉及一些大学生。项目结果和既定的研究地点将用于动手实践林记研究生培训。该项目与两个湖泊的土地经理合作，将提供详细的物理基线，以告知未来水质监测的水域，并将为明尼阿波利斯市环境教育外展计划做出贡献。人们认为光含量是富铁的前寒武纪海洋中主要生产力的主要途径。然而，当前的类似物 - meromic铁质湖 - 要么受到光含量的光限制，要通过主要是硫磺的光合途径固定碳，或者位于不适合季节性监测的区域。布朗尼湖具有足够的光线和丰富的无氧光养殖（包括光铁植物），而较深的峡谷湖具有扩展的氧化氧化转变区，而养分比布朗尼湖低得多。这些湖泊共同构成了一系列条件，以调查对照养分水平，生理学和季节性在光相营养原发性生产力和甲烷循环方面具有的对照。该团队将监视来自布朗尼和峡谷湖水柱的水和碳同位素地球化学，微生物群落组成以及元素化妆/矿物学，以确定：（1）调节光子植物的物理条件和活性的物理条件，（2）居民微生物在生物和碳中的作用（2）居民在生物和碳中的作用，社区可能已经留在富含铁的铁质沉积物中，例如带状铁地层（BIF），以及（4）光含量营养和甲烷生成/甲烷的同位素烙印对碳和铁循环。

项目成果

Biogeochemical and physical controls on methane fluxes from two ferruginous meromictic lakes

• DOI: 10.1111/gbi.12365
• 发表时间: 2019-10
• 期刊: Geobiology
• 影响因子: 3.7
• 作者: N. Lambrecht;S. Katsev;C. Wittkop;S. Hall;C. Sheik;A. Picard;M. Fakhraee;E. Swanner

The biogeochemistry of ferruginous lakes and past ferruginous oceans

• DOI: 10.1016/j.earscirev.2020.103430
• 发表时间: 2020-12
• 期刊: Earth-Science Reviews
• 影响因子: 12.1
• 作者: E. Swanner;N. Lambrecht;C. Wittkop;C. Harding;S. Katsev;J. Torgeson;S. Poulton

Geochemical data from sediments and porewaters from ferruginous and meromictic Brownie Lake, Minnesota, U.S.A.

来自美国明尼苏达州铁质和半重质布朗尼湖沉积物和孔隙水的地球化学数据

• DOI: 10.6073/pasta/68b50baa0a767ab33f2b7dd91948036e
• 发表时间: 2022
• 期刊: Environmental Data Initiative
• 作者: Swanner, Elizabeth D.;Islam, Raisa;Ledesma, Gabrielle;Wittkop, Chad;Akam, Sajjad;Eitel, Eryn;Katsev, Sergei;Johnson, Ben;Poulton, Simon;Bray, Andy
• 通讯作者: Bray, Andy

Water properties of Brownie Lake, MN and Canyon Lake, MI from 2015-2019

2015-2019 年明尼苏达州布朗尼湖和密歇根州峡谷湖的水特性

• DOI: 10.6073/pasta/4eaf698b4efbaf793b83d95f464d1672
• 发表时间: 2021
• 期刊: Environmental Data Initiative
• 作者: Swanner, Elizabeth D;Lambrecht, Nicholas;Wittkop, Chad;Katsev, Sergei;Ledesma, Gabrielle;Leung, Tania
• 通讯作者: Leung, Tania

Evaluation of preservation protocols for oxygen‐sensitive minerals within laminated aquatic sediments

层状水生沉积物中氧敏感矿物的保存方案评估

• DOI: 10.1002/lom3.10533
• 发表时间: 2023
• 期刊: Limnology and Oceanography: Methods
• 作者: Ledesma, Gabrielle;Islam, Raisa;Swanner, Elizabeth D.
• 通讯作者: Swanner, Elizabeth D.