Large Scale Sequencing to Unravel Carbon Cycling in the Elbe estuary (Micro)biota

河口覆盖了全球五分之一以上的陆地表面，是全球碳固定的关键驱动力。它们的特点是由于不同的外部强迫(例如淡水排放、洋流、潮汐能量)而具有高度的时间动力学，以及在盐度、水动力和氧气可获得性(河口梯度)方面具有明显的空间梯度。沿着河口梯度，潮间带生态系统(有植被的潮汐沼泽、有微型底栖植物群落的潮间带)和潮下航道(底栖和远洋生态系统)紧密相连，生产、运输和加工大量陆地和水生有机物质。控制河口C循环的关键过程仍然知之甚少，尽管最近的研究表明，植物-浮游植物-微生物相互作用和草食作为潮汐沼泽和河口航道C通量的控制因素具有潜在的高度相关性。该提案和RTG 2530旨在系统分析生物群对河口C循环的影响，考虑到河口的梯度和动态、河口生态系统之间的联系以及全球变化的影响。通过对易北河口沿岸的样本进行测序，我们将描述浮游植物、细菌、古生菌和真菌(例如，在土壤、水、根际、粪便样本中)的门和亚门水平上的优势微生物。我们将破译积极参与水、土壤、沉积物和河口植物根际碳循环的代谢途径。我们将看到盐度梯度对小型哺乳动物的粪便微生物群和鱼类的鳃微生物群的影响。我们还将描述易北河口主要鱼类的广泛转录应激状态。

Estuaries cover more than one fifth of the global terrestrial surfaces and are key drives in global carbon fixation. They are characterized by high temporal dynamics due to variable external forcing (e.g. freshwater discharge, ocean currents, tidal energy) and by pronounced spatial gradients in, e.g., salinity, hydrodynamics, and oxygen availability (estuarine gradients). Along estuarine gradients, ecosystems of intertidal areas (vegetated tidal marshes, intertidal flats with microphytobenthos communities) and subtidal channels (benthic and pelagic ecosystems) are tightly linked and produce, transport and process large amounts of terrestrial and aquatic organic matter. Key processes governing estuarine C cycling are still poorly understood, although recent research has exemplified the potential high relevance of plant- and phytoplankton-microbe interactions and herbivory as controls of C fluxes in tidal marshes and estuarine channels. The proposal together with the RTG 2530 aims to systematically analyze biota-mediated effects on estuarine C cycling considering estuarine gradients and dynamics, linkages among estuarine ecosystems, and effects of global change. Through sequencing of samples along the Elbe Estuary we will describe the dominant microorganisms on a phylum and subphylum level for phytoplankton, bacteria, archaea and fungi (e.g., in soil, water, rhizosphere, fecal samples). We will decipher the metabolic pathways actively involved in carbon cycling in water, soils, sediments and estuarine plant rhizospheres. We will see the impact of salinity gradient on the fecal microbiota of small mammals and the gill microbiome of fish. We will also describe the broad transcriptomic stress status of the main fish species in the Elbe estuary.