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.

现在，有毒的蓝细菌有害藻类开花（CHAB）是一个全球问题，它对人类和水上生物体构成危险，包括威胁生命的疾病，海滩封闭，健康警报和饮用水处理厂的封闭植物。 该项目着重于了解Chabs中存在的微生物与他们居住的湖泊化学反应所需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，命运和作用，这是对这些花朵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（Lake Erie）进行，伊利湖（Lake Erie）是为1100万人的饮用水来源，每年受到CHAB的威胁。 结果将直接整合到两个水质模型中，这些模型被水管理者和其他利益相关者广泛使用。 该项目将支持对两名博士学位学生的培训，包括第一代大学与会者，以及来自地球科学中代表性不足的本科生。 研究还将融入旨在增加地球科学多样性的外展活动，通过涉及妇女和在K-12中代表性不足的少数群体以及大学和成人教育环境。该项目的总体目标是确定过氧化氢（H2O2）对氰基细菌社区组成和近岸生态系统中的作用。 伊利湖（Lake Erie）的初步结果表明，主要的主要生产者依靠异营养细菌从瞬时较高的环境水平中降低H2O2，这可能会抑制蓝细菌群落的成员。 这表明H2O2在水生微生物生态学中起着重要的作用，并且仍然对其作用还不足。 现场抽样，实验和最先进的“ - 词”的结合将用于检验总体假设，即H2O2分解杂营“助手”是微生物相互作用以及社区结构和功能的重要决定因素。 将研究伊利湖，因为（i）这是一个模型系统，用于浅层沿海地区接受高地面营养径流，（ii）它为比较研究提供了强大的近海近海梯度，以及（iii）现有的采样基础架构，存档的样品和初步数据。 现场和实验室实验和测量将集成以回答以下问题：Q1：是什么驱动H2O2浓度的时间动力学？ 问题2：哪些酶和生物负责通过生物H2O2衰减保护社区？ 问题3：助手对H2O2的保护如何影响社区的组成和功能？ 这项研究将在盛开的不同点上对培养物和自然水域进行受控的实验实验。 H2O2浓度和生产率和衰减率的测量以及支持化学和生物学测量值将用于评估H2O2的主要来源和水槽。 分子工具将用于确定H2O2衰减的途径以及H2O2对蓝细菌群落组成功能的影响。 同时，将通过实验评估不同H2O2浓度对主要蓝细菌生长速率的影响。 这些实验结果将通过与该沿海生态系统中空间，时间和化学梯度的田间样品的微生物群落的结构和功能进行比较。 将H2O2与自然系统中的“ - 组”相结合的方法是新颖的，它将促进我们对微生物群落组成和功能之间关系的基本知识和理解。

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.

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.

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.

The genetic and ecophysiological diversity of Microcystis

• DOI: 10.1111/1462-2920.15615
• 发表时间: 2021-06-14
• 期刊: ENVIRONMENTAL MICROBIOLOGY
• 影响因子: 5.1
• 作者: Dick, Gregory J.;Duhaime, Melissa B.;Denef, Vincent J.
• 通讯作者: Denef, Vincent J.