Polysaccharide utilization mechanisms under permanent low-temperature conditions in the Southern Ocean

南大洋永久低温条件下的多糖利用机制

• 批准号: 315079146
• 负责人: Professor Dr. Thomas Schweder
• 金额: --
• 依托单位: Institut für Pharmazie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/315079146?language=en
• 关键词: Polysaccharide; utilization; mechanisms; under; permanent

The Antarctic Ocean, also known as the Southern Ocean, plays a critical role in the biological pump function of the oceans. It is assumed that the Southern Ocean accounts for about 30% of global ocean uptake of CO2 and is thus crucial for buffering of increasing CO2 levels in the atmosphere. The degradation of biopolymeric material produced by photosynthetic primary production regulates how much carbon is stored in the oceans. However, the molecular and physiological mechanisms that allow cold-adapted bacteria to rapidly dissolve and catabolize complex polysaccharides from algae remain unknown. We have isolated a psychrophilic marine Gammaproteobacterium, Pseudoalteromonas halplanktis ANT/505, from Antarctic waters, which shows a broad capacity to catabolize polysaccharides. This bacterium, which is abundantly detectable in the surface water of the Southern Ocean, is amendable to genetic manipulation and is proposed here as a model organism to reveal psychrophilic adaptations that determine polysaccharide turnover in Polar Regions. The project aims to elucidate specific mechanisms of marine polysaccharide utilization of this model bacterium. We will functionally characterize pectin- and alginate-specific transport and degradation pathways. We will compare these pathways with other polysaccharide utilization mechanisms of P. haloplanktis by proteogenomic analyses. We will investigate how multi-modular enzymes enable an increased interaction with the substrate and support polysaccharide degradation in a dilute marine environment. Finally, the function of extracellular vesicles and appendages for pectin- and alginate-specific polysaccharide degradation processes will be exemplarily investigated under low-temperature conditions. This project will investigate biological processes, which are relevant for the carbon cycle in the Southern Ocean. The results of this project will enable a better understanding of polysaccharide catabolism processes in the polar sea, which is a prerequisite for the characterization of the biological pump function of the Southern Ocean under climate changing conditions.

南极洋，也被称为南大洋，在海洋的生物泵功能中发挥着关键作用。据推测，南大洋约占全球海洋吸收二氧化碳的30%，因此对缓冲大气中不断增加的二氧化碳水平至关重要。光合初级生产产生的生物聚合物材料的降解调节了海洋中储存的碳量。然而，允许冷适应细菌快速溶解和分解代谢来自藻类的复杂多糖的分子和生理机制仍然未知。我们从南极沃茨中分离到一株嗜冷海洋γ-变形杆菌Pseudoalteromonas halpatitis ANT/505，它具有广泛的分解代谢多糖的能力。这种细菌，这是大量检测到的表面水的南大洋，是可遗传操作，并提出在这里作为一个模式生物揭示嗜冷适应，确定多糖营业额在极地地区。本项目旨在阐明该模式菌利用海洋多糖的具体机制。我们将在功能上表征果胶和藻酸盐的特定运输和降解途径。我们将通过蛋白质基因组学分析比较这些途径与其他的多糖利用机制。我们将研究多模块酶如何能够增加与底物的相互作用，并支持在稀海洋环境中的多糖降解。最后，果胶和藻酸盐特异性多糖降解过程的细胞外囊泡和附属物的功能将在低温条件下进行示例性研究。该项目将调查与南大洋碳循环有关的生物过程。该项目的成果将使人们能够更好地了解极地海洋中的多糖催化过程，这是确定气候变化条件下南大洋生物泵功能特征的先决条件。