The role of marine fungi in the microbial loop

海洋真菌在微生物循环中的作用

• 批准号: 520750462
• 负责人: Professor Dr. Tilmann Harder
• 金额: --
• 依托单位: Arbeitsgruppe Molekulare Ökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/520750462?language=en
• 关键词: role; marine; fungi; microbial; loop

Marine food webs are largely driven by the interplay of carbon fixation, primary production, and remineralization of organic matter. These organic substances are chemically diverse and occur in dissolved, adsorbed or aggregated forms. They are degraded by a wide range of heterotrophic microorganisms. The role of bacteria in this process is comparatively well understood. They form metabolic subpopulations with complementary decomposition strategies, resulting in so-called metabolic guilds. Although marine fungi are ubiquitously present in pelagic microbial communities, their role in the microbial loop is still largely unknown. Whether and how fungi interact with bacteria in the microbial loop influences the efficiency of marine carbon transformation and is thus of high scientific value. Here we hypothesize that (1) fungi and bacteria form specific metabolic guilds depending on the available organic carbon source, and (2) thus increase the degradation potential of the guild via interkingdom interactions. This is investigated with time series in-vitro experiments. For this purpose, seawater will be sampled during geographically different phytoplankton bloom events and concentrated to a microbial inoculum of fungi and bacteria. The inoculum will be used to inoculate different dissolved organic substrates, representative of phytoplankton exudates, to establish specific metabolic guilds. These guilds will then be studied for phylogenetic analysis by tag-sequencing and chemical analyses by LC-MS and NMR of their degradation products.

海洋食物网在很大程度上是由碳固定、初级生产和有机物的再矿化的相互作用驱动的。这些有机物质的化学性质多种多样，以溶解、吸附或聚集的形式存在。它们被广泛的异养微生物降解。细菌在这一过程中的作用是比较好理解的。它们形成具有互补分解策略的代谢亚群，从而形成所谓的代谢行会。虽然海洋真菌普遍存在于浮游微生物群落中，但它们在微生物循环中的作用在很大程度上仍然未知。微生物环中真菌与细菌之间是否以及如何相互作用影响着海洋碳转化的效率，具有很高的科学价值。在这里，我们假设：（1）真菌和细菌形成特定的代谢集团取决于可用的有机碳源，（2）因此，通过界间相互作用增加了集团的降解潜力。这是研究与时间序列的体外实验。为此，将在不同地理位置的浮游植物水华期间对海水进行采样，并将其浓缩成真菌和细菌的微生物接种物。接种物将被用来接种不同的溶解有机基质，代表浮游植物分泌物，以建立特定的代谢群。然后将通过标签测序和LC-MS化学分析以及其降解产物的NMR研究这些行业协会的系统发育分析。