Characterizing mycoplankton and the mycobenthos in the Benguela upwelling system

本格拉上升流系统中浮游真菌和底栖真菌的特征

• 批准号: 420565559
• 负责人: Professor Dr. William Orsi, Ph.D.
• 金额: --
• 依托单位: Sektion Paläontologie und Geobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/420565559?language=en
• 关键词: Characterizing; mycoplankton; mycobenthos; Benguela; upwelling

The "biological pump" exports biologically produced organic matter in the surface ocean to the deep sea and seafloor. The efficiency of the biological pump exerts a strong influence on Earth’s climate by controlling how much carbon is exported to the deep sea and biodegradation of the organic matter deposited in sediments controls massive (teragrams) sinks of organic carbon that are ultimately sequestered in the subsurface. The mycoplankton and mycobenthos are two groups of heterotrophic eukaryotic microbes that are hypothesized to help control the flux of carbon in seawater and sediments, but the abundance, diversity, and activity of these groups are poorly understood.Mycoplankton and the mycobenthos are Fungi and fungal-analogs that live in seawater (mycoplankton) and sediments (mycobenthos), respectively. They have been detected in several locations of the world’s oceans. Thus, through their metabolism they are hypothesized to help control how much organic matter is ultimately buried and sequestered in the seafloor on a global scale. However, mycoplankton and the mycobenthos have not yet been characterized in the Benguela upwelling system. Because this is one of the most productive upwelling regions of the ocean, the overarching research aim of the proposed work is to quantify mycoplankton and mycobenthos diversity and metabolic activity, in order to better define their ecological role in this important oceanographic location. To this end, I participated in the Meteor Reise M148-2 to the Benguela upwelling system ('EreBUS': Processes controlling the Emissions of greenhouse gases from the Benguela Upwelling System) from July 2nd – July 20th, 2018. Waters were sampled from six sites exhibiting vertical oxygen gradients that were observed in the water column on the Namibian shelf. In addition, two 26 cm deep sediment cores were obtained from one site below the oxygen minimum zone on the shelf. Water samples up to a depth of 1,000 m were also collected at eight offshore sites in the Angola Gyre, as the Meteor transited from Namibia to the Canary Islands. In total there are 90 samples that now await processing, and I propose to use state-of-the-art quantitative DNA and RNA sequencing techniques to determine the abundance, activity, and diversity of the mycoplankton and mycobenthos.The proposed project will address the questions: What are the dominant groups of metabolically active mycoplankton and mycobenthos in the Benguela upwelling system? What are the biogeochemically relevant metabolic features of mycoplankton and mycobenthos in the Benguela upwelling system? Addressing these questions is important because it will improve our understanding of a new biological mechanism (mycoplankton and mycobenthos) within the biological pump, a global process that helps control Earth’s climate over geological timescales.

“生物泵”将海洋表层生物产生的有机物输送到深海和海底。生物泵的效率通过控制向深海输出的碳量对地球气候产生强烈影响，沉积物中沉积的有机物的生物降解控制了最终被隔离在地下的大量（兆克）有机碳汇。浮游真菌和底栖真菌是两类异养真核微生物，它们被认为有助于控制海水和沉积物中碳的通量，但对这两类微生物的丰度、多样性和活性知之甚少。浮游真菌和底栖真菌是分别生活在海水（浮游真菌）和沉积物（底栖真菌）中的真菌和真菌类似物。在世界海洋的几个地方都发现了它们。因此，通过它们的新陈代谢，它们被假设有助于控制在全球范围内最终被掩埋和隔离在海底的有机物的数量。然而，本格拉上升流系统中浮游菌和底栖菌尚未被发现。由于这是海洋中最具生产力的上升流区域之一，因此拟议工作的总体研究目标是量化浮游菌和底栖菌的多样性和代谢活动，以便更好地确定它们在这一重要海洋位置的生态作用。为此，我于2018年7月2日至7月20日参加了对本格拉上升流系统（“EreBUS”：控制本格拉上升流系统温室气体排放的过程）的Meteor Reise M148-2。从纳米比亚大陆架水柱中观察到的6个显示垂直氧梯度的地点取样。此外，在陆架上氧最低带以下的一个地点获得了两个26 cm深的沉积物岩心。在流星号从纳米比亚到加那利群岛的过程中，在安哥拉环流的8个近海地点也收集了深度达1000米的水样。现在总共有90个样本等待处理，我建议使用最先进的定量DNA和RNA测序技术来确定浮游菌和底栖菌的丰度、活性和多样性。拟议的项目将解决以下问题：在本格拉上升流系统中，代谢活跃的浮游菌和底栖菌的优势群体是什么？Benguela上升流系统中浮游真菌和底栖真菌的生物地球化学相关代谢特征是什么？解决这些问题很重要，因为它将提高我们对生物泵内新的生物机制（浮游菌和底栖菌）的理解，这是一个全球性的过程，有助于在地质时间尺度上控制地球气候。