The role of heterotrophic bacteria in protecting cyanobacteria from hydrogen peroxide in coastal systems.

异养细菌在保护蓝藻免受沿海系统过氧化氢侵害中的作用。

• 批准号: 1736629
• 负责人: Gregory Dick
• 金额: $ 87.41万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736629&HistoricalAwards=false
• 关键词: role; heterotrophic; bacteria; protecting; cyanobacteria

Toxic cyanobacterial harmful algal blooms (CHABs) are now a worldwide problem that poses dangers for humans and aquatic organisms including life-threatening sickness, beach closures, health alerts, and drinking water treatment plant closures. This project focuses on the basic science needed to understand interactions between the microorganisms present in CHABs and the chemistry of the lakes they inhabit. In particular, it will study the sources, fate, and effects of hydrogen peroxide, which is a potentially important control on the toxicity and species present within these blooms. This research will be conducted in Lake Erie, a source of drinking water for 11 million people that is threatened by CHABs annually. Results will be directly integrated into two water quality models that are widely used by water managers and other stakeholders. This project will support the training of two PhD students, including a first-generation college attendee, and undergraduate students from backgrounds that are underrepresented in the earth sciences. Research will also be integrated into outreach aimed at increasing diversity in the earth sciences by involving women and underrepresented minorities in K-12 as well as college and adult educational settings.The overall goal of this project is to determine the influence of hydrogen peroxide (H2O2) on cyanobacterial community composition and function in nearshore ecosystems. Preliminary results from Lake Erie show that dominant primary producers rely on heterotrophic bacteria to draw down H2O2 from transiently high environmental levels that are likely inhibitory to members of the cyanobacterial community. This suggests that H2O2 plays important and still poorly understood roles in aquatic microbial ecology. A combination of field sampling, experiments, and state-of-the art "-omics" will be used to test the overall hypothesis that H2O2 decomposition by heterotrophic "helpers" is an important determinant of microbial interactions and community structure and function. Lake Erie will be studied because (i) it is a model system for shallow coastal areas receiving high terrestrial nutrient runoff, (ii) it offers strong inshore-offshore gradients of light and nutrients for comparative studies, and (iii) existing sampling infrastructure, archived samples, and preliminary data can be leveraged. Field and laboratory experiments and measurements will be integrated to answer the following questions: Q1: What drives the temporal dynamics of H2O2 concentrations? Q2: Which enzymes and organisms are responsible for protecting the community via biological H2O2 decay? Q3: How does protection from H2O2 by helpers influence the composition and function of the community? The study will perform controlled lab experiments on cultures and on natural waters during different points of the bloom. Measures of H2O2 concentrations and rates of production and decay, along with supporting chemical and biological measurements, will be used to assess the major sources and sinks of H2O2. Molecular tools will be used to determine the pathways underpinning H2O2 decay and the effect of H2O2 on cyanobacterial community composition function. In parallel, impacts of varying H2O2 concentrations on growth rates of major cyanobacteria will be assessed experimentally. These experimental results will be placed into context through comparisons with the structure and function of microbial communities from field samples across spatial, temporal, and chemical gradients in this coastal ecosystem. The approach of integrating studies of H2O2 with "-omics" in natural systems is novel, and will advance our fundamental knowledge and understanding of the relationship between microbial community composition and function.

有毒蓝藻有害水华(CHAB)现在是一个世界性问题，对人类和水生生物构成危险，包括危及生命的疾病、海滩关闭、健康警报和饮用水处理厂关闭。该项目侧重于了解CHAB中存在的微生物与它们所栖息的湖泊化学之间的相互作用所需的基础科学。特别是，它将研究过氧化氢的来源、命运和影响，这是对这些水华中存在的毒性和物种的潜在重要控制。这项研究将在伊利湖进行，伊利湖是每年受到CHAB威胁的1100万人的饮用水来源。结果将直接纳入水资源管理者和其他利益攸关方广泛使用的两个水质模型。该项目将支持对两名博士生的培训，其中包括一名第一代大学学员，以及来自地球科学专业背景不足的本科生。这一项目的总体目标是确定过氧化氢(过氧化氢)对近岸生态系统蓝藻群落组成和功能的影响。伊利湖的初步结果表明，占主导地位的初级生产者依赖异养细菌从短暂的高环境水平中吸收过氧化氢，这可能对蓝藻群落的成员具有抑制作用。这表明，过氧化氢在水生微生物生态中发挥着重要的作用，但人们对此知之甚少。结合现场采样、实验和最先进的“组学”，将检验异养“辅助者”分解过氧化氢是微生物相互作用和群落结构和功能的重要决定因素这一总体假设。将对伊利湖进行研究是因为：(I)它是一个浅海沿岸地区接收高陆地营养物质径流的模型系统；(Ii)它为比较研究提供了强大的近岸-近海光线和营养物质梯度；(Iii)现有的采样基础设施、存档样本和初步数据可以利用。将结合现场和实验室实验和测量来回答以下问题：问题1：是什么驱动了过氧化氢浓度的时间动态？问2：哪些酶和生物体负责通过生物过氧化氢腐烂来保护群落？问题3：帮助者对过氧化氢的保护如何影响社区的组成和功能？这项研究将在水华的不同时间点对培养物和自然水域进行受控实验室实验。将使用过氧化氢浓度、产生率和衰减率的测量，以及辅助的化学和生物测量，来评估过氧化氢的主要来源和汇。分子工具将被用来确定支持H_2O_2衰变的途径以及H_2O_2对蓝藻群落组成功能的影响。同时，将通过实验评估不同的过氧化氢浓度对主要蓝藻生长速度的影响。这些实验结果将通过与这个沿海生态系统中跨空间、时间和化学梯度的野外样本的微生物群落的结构和功能进行比较而被放入背景中。将过氧化氢与自然系统中的组学研究相结合是一种新颖的方法，它将促进我们对微生物群落组成和功能之间关系的基础知识和理解。

项目成果

Chlorophyll nitrogen isotope values track shifts between cyanobacteria and eukaryotic algae in a natural phytoplankton community in Lake Erie

• DOI: 10.1016/j.orggeochem.2018.12.006
• 发表时间: 2019-02
• 期刊: Organic Geochemistry
• 影响因子: 3
• 作者: Jenan J. Kharbush;Derek J. Smith;McKenzie A Powers;H. Vanderploeg;D. Fanslow;R. Robinson;G. Dick;A. Pearson

Genotype and host microbiome alter competitive interactions between Microcystis aeruginosa and Chlorella sorokiniana

• DOI: 10.1016/j.hal.2020.101939
• 发表时间: 2020-11-01
• 期刊: HARMFUL ALGAE
• 影响因子: 6.6
• 作者: Schmidt, Kathryn C.;Jackrel, Sara L.;Denef, Vincent J.
• 通讯作者: Denef, Vincent J.

Models predict planned phosphorus load reduction will make Lake Erie more toxic

• DOI: 10.1126/science.abm6791
• 发表时间: 2022-05-27
• 期刊: SCIENCE
• 影响因子: 56.9
• 作者: Hellweger, Ferdi L.;Martin, Robbie M.;Wilhelm, Steven W.
• 通讯作者: Wilhelm, Steven W.

Uptake of Phytoplankton-Derived Carbon and Cobalamins by Novel Acidobacteria Genera in Microcystis Blooms Inferred from Metagenomic and Metatranscriptomic Evidence

• DOI: 10.1128/aem.01803-21
• 发表时间: 2022-07-05
• 期刊: APPLIED AND ENVIRONMENTAL MICROBIOLOGY
• 影响因子: 4.4
• 作者: Smith，Derek J.;Kharbush，Jenan J.;Dick，Gregory J.
• 通讯作者: Dick，Gregory J.

Controls on the photochemical production of hydrogen peroxide in Lake Erie

伊利湖光化学过氧化氢生产的控制

• DOI: 10.1039/d2em00327a
• 发表时间: 2022
• 期刊: Environmental Science: Processes & Impacts
• 作者: Pandey, Dhurba Raj;Polik, Catherine;Cory, Rose M.
• 通讯作者: Cory, Rose M.