Determinants of Community Structure, Function and Succession of Freshwater Microorganisms Colonizing Lake Snow

雪湖淡水微生物群落结构、功能和演替的决定因素

• 批准号: 393798666
• 负责人: Dr. Mina Bizic
• 金额: --
• 依托单位: Abteilung 3: Plankton- und mikrobielle Ökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/393798666?language=en
• 关键词: Determinants; Community; Structure; Function; Succession

In the proposed research, I aim to conduct a temporal study on the microbial degradation of macroscopic organic aggregates in freshwater lakes, also known as Lake Snow. I will study Lake Snow at near-in-situ conditions using a flow-through rolling tank we have recently developed. I aim to determine the factors responsible for microbial succession on sinking / degrading particles while accounting for single particle heterogeneity both in community composition as well as in activity. Lake Snow makes up a significant portion of the aquatic particulate organic matter and consists of different source particles (e.g. phytoplankton cells, zooplankton-carcasses and allochthonous organic matter). Concentrations of organic and inorganic molecules, on Lake Snow, often exceed background levels by 2-4 orders of magnitude providing associated microorganisms with a potent energy, carbon and nutrient source. As a result, these particles are heavily colonized by heterotrophic bacteria that play an essential role in their degradation. The community structure of these bacteria differs between individual particles, but yet the driving force behind this observation has not been studied. The microbial community on particles changes in time, a succession process attributed to changes in carbon quality; my preliminary results, however, show no changes in expression of related microbial genes over at least 8 days. Therefore, I hypothesize that a major force in shaping the particle-associated community is inter-organisms interactions. These include Bacteria-Eukarya, Bacteria-Bacteria and Bacteria-Viruses interactions. To evaluate the fate of Lake Snow under natural conditions as well as to achieve a better understanding of the processes determining the nature of the associated microbial community in space and time, I plan to: A) Determine the effects of particle sources on microbial colonization heterogeneity; B) Determine the heterogeneity in microbial activity among particles of the same and different source; C) Assess the contribution of inter-organisms interactions to succession events of Lake Snow colonizing microbial communities in comparison to changes in carbon quality. To address all topics, I will study multiple, lab-made, individual particles using novel flow-through rolling tank systems coupled with community fingerprinting, activity measurements, transcriptomics and organic matter characterization. The results of this study will provide crucial knowledge on microbial mechanisms at the microscale to better understand the role of aquatic systems in organic matter cycling and storage.

在拟议的研究中，我的目标是进行一个时间的研究宏观有机聚集体在淡水湖，也被称为湖雪的微生物降解。我将研究湖雪在近原位条件下使用流通滚动坦克，我们最近开发的。我的目的是确定负责下沉/降解颗粒的微生物演替的因素，同时占单颗粒的异质性，无论是在社区组成，以及在活动。雪湖构成了很大一部分的水生颗粒有机物，并由不同的源颗粒（如浮游植物细胞，动物尸体和外来有机物）。雪湖上有机和无机分子的浓度通常超过背景水平2-4个数量级，为相关微生物提供了有效的能量，碳和营养源。因此，这些颗粒被异养细菌大量定殖，这些细菌在其降解中起着至关重要的作用。这些细菌的群落结构在单个颗粒之间存在差异，但尚未研究这一观察结果背后的驱动力。颗粒上的微生物群落随着时间的推移而变化，这是一个由碳质量变化引起的演替过程;然而，我的初步结果显示，至少8天内相关微生物基因的表达没有变化。因此，我假设，在塑造粒子相关的社区的主要力量是生物体间的相互作用。这些包括细菌-真核生物、细菌-细菌和细菌-病毒相互作用。为了评估自然条件下雪湖的命运，以及更好地理解决定相关微生物群落在空间和时间上的性质的过程，我计划：A）确定颗粒源对微生物定殖异质性的影响; B）确定相同和不同来源的颗粒之间微生物活性的异质性; C）评估与碳质量变化相比，生物间相互作用对雪湖殖民微生物群落演替事件的贡献。为了解决所有的问题，我将研究多个，实验室制造的，单独的颗粒使用新的流通滚动槽系统，再加上社区指纹，活动测量，转录组学和有机物表征。这项研究的结果将提供微尺度微生物机制的关键知识，以更好地了解水生系统在有机物循环和储存中的作用。