Linking bacterial community assembly and dissolved organic C dynamics along freshwater networks in boreal landscapes

将北方景观中沿淡水网络的细菌群落组装和溶解有机碳动态联系起来

• 批准号: RGPIN-2017-06262
• 负责人: delGiorgio, Paul
• 金额: $ 4.23万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765196
• 关键词: Linking; bacterial; community; assembly; dissolved

Bacteria play a major role in the functioning of all aquatic systems. Planktonic and benthic bacteria are responsible for much of the nutrient cycling, the transformation and degradation of organic matter and for a significant portion of the total energy flux in these ecosystems. One of the key challenges in contemporary microbial ecology has been to understand the factors of structure these functionally complex and extremely diverse communities. For aquatic bacterial communities, this implies understanding the origin of the microbes that we observe, their movement within the interconnected aquatic network, and their responses to the various environmental conditions that they encounter during transit. Most current studies lack this dynamic, network context, and therefore offer a fragmented and partial perspective of aquatic bacterial community assembly. Here I propose a program that will explicitly take a whole network approach to exploring bacterial community assembly, where we will reconstruct the taxonomic, metabolic and functional microbial successions that occur along the aquatic continuum, from soils to the sea through interconnected rivers and lakes, and identify the main underlying drivers. We will in parallel assess the chemical succession that occurs in the molecular structure and reactivity of the dissolved organic carbon pool (DOC) along this aquatic continuum, with the objective of determining the connections and interactions that may exist between these two key components of all aquatic ecosystems. This integrated watershed perspective of aquatic bacterial communities and organic C biogeochemistry was technically and financially unthinkable only a few years back, but is now enabled by new generation approaches that have increased our capacity of assessing the structure of both bacteria and DOM with unprecedented detail and at a fraction of the cost. The proposed program will benefit from an ongoing research platform that will provide a large-scale, integrated sampling of rivers, wetlands and lakes along the entire aquatic continuum in a large boreal watershed of Québec. We will carry out highly spatially resolved sampling along this continuum, and will apply a combination of high-throughput sequencing and genomic microarray technologies, metabolic and physiologic measurements of bacterial communities, and advanced analytical approaches to characterize the molecular composition of DOC. The proposed work is a logical expansion of the research that our group has done over the past decade, and will establish the foundation for understanding the assembly of both bacteria and organic pools within complex aquatic networks, their respective environmental controls, and the possible links that exist between them. The research will likely lead to a reassessment of current models and paradigms of bacterial succession, community assembly and links to resources.

细菌在所有水生系统的功能中起着重要作用。浮游和底栖细菌负责这些生态系统中的大部分养分循环、有机物的转化和降解，并负责总能量通量的很大一部分。当代微生物生态学的关键挑战之一是了解这些功能复杂且极其多样化的群落的结构因素。对于水生细菌群落，这意味着了解我们观察到的微生物的起源，它们在相互连接的水生网络中的运动，以及它们对运输过程中遇到的各种环境条件的反应。目前大多数研究缺乏这种动态的网络环境，因此提供了一个支离破碎的和部分的角度来看水生细菌群落组装。在这里，我提出了一个计划，将明确采取整个网络的方法来探索细菌群落组装，在那里我们将重建分类，代谢和功能微生物的演替发生沿着水生连续体，从土壤到海洋，通过相互连接的河流和湖泊，并确定主要的潜在驱动因素。我们将在平行的化学演替发生在溶解有机碳池（DOC）的分子结构和反应性，沿沿着这一水生连续体，以确定所有水生生态系统的这两个关键组成部分之间可能存在的连接和相互作用的目标进行评估。这一综合性的流域观点的水生细菌群落和有机碳地球化学是技术和财政上不可想象的只有几年前，但现在是通过新一代的方法，增加了我们的能力，评估细菌和DOM的结构与前所未有的细节和成本的一小部分。拟议的方案将受益于一个正在进行的研究平台，该平台将提供魁北克北部大流域整个水生连续体中河流、湿地和湖泊沿着的大规模综合采样。我们将进行高度空间分辨采样沿着这一连续体，并将应用高通量测序和基因组微阵列技术，代谢和生理测量的细菌群落，先进的分析方法来表征DOC的分子组成的组合。拟议的工作是我们小组在过去十年中所做研究的逻辑扩展，并将为理解复杂水生网络中细菌和有机池的组装，各自的环境控制以及它们之间存在的可能联系奠定基础。这项研究可能会导致重新评估目前的细菌演替，群落组装和资源联系的模型和范例。