Siderophore mediated iron acquisition of psychrophilic Antarctic marine bacteria

铁载体介导嗜冷南极海洋细菌的铁获取

• 批准号: 442928823
• 负责人: Professor Dr. Tilmann Harder
• 金额: --
• 依托单位: Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/442928823?language=en
• 关键词: Siderophore; mediated; iron; acquisition; psychrophilic

Iron is a highly limited resource in large areas of the Southern Ocean. To compete for the limited and often localized influx of iron, bacteria have developed various biochemical strategies to capture iron and transport it into the cell. The aim of this project is to purify and structurally identify bacterially produced iron ligands, so called siderophores, of a phylogenetic spectrum of cultivable psychrophilic Antarctic marine bacteria obtained from divergent Antarctic environments. A consequential objective is then to correlate iron uptake by different siderophores among these bacteria with environmental parameters (iron stress, carbon availability, salinity and temperature). With this approach, we will unravel the spectrum of iron binding ligands used by Antarctic bacteria and ultimately contribute to a better understanding of microbial adaptations to the extreme environments of the SO.Specifically, 384 bacterial isolates obtained from the Southern Ocean will be cultured under growth regimes reflecting iron depletion. Indicator assays in combination with voltammetry and mass spectrometry will be used to detect siderophores in the bacterial supernatants and cell pellets. This approach will allow us to differentiate siderophore types across cultivable bacterial lineages of Antarctic origin and/or their original habitats. We will structurally elucidate novel siderophores by NMR and MS and purify these and known siderophores for reference standards used for quantitative analyses and experimental determination of physicochemical characteristics. One major aim is to characterize diffusion and adsorption traits for different siderophore types under conditions representative of SO habitats. We will study how environmental parameters (temperature, salinity) influence the iron capturing performance and diffusive losses for each ligand type. These general siderophore characteristics will be used to interpret results from experiments testing bacterial growth and siderophore production dependent on a range of temperature, salinity and ice regimes. This study will ultimately improve existing cellular iron uptake models, increase our knowledge of iron uptake strategies of psychrophilic bacteria and ultimately contribute to a better process understanding of the microbially driven Antarctic iron cycle, therefore addressing several of the central criteria of the DFG SPP call.

在南大洋的大片海域，铁是一种非常有限的资源。为了争夺有限且通常是局部流入的铁，细菌已经发展出各种生化策略来捕获铁并将其运输到细胞中。该项目的目的是纯化和从结构上鉴定从不同的南极环境中获得的可培养的南极海洋嗜冷细菌的系统发育谱中细菌产生的铁配体，即所谓的铁载体。随后的一个目标是将这些细菌中不同铁载体的铁摄取与环境参数（铁胁迫、碳可用性、盐度和温度）联系起来。通过这种方法，我们将解开南极细菌使用的铁结合配体的光谱，并最终有助于更好地理解微生物对SO极端环境的适应。具体来说，从南大洋获得的384个细菌分离株将在反映铁耗尽的生长制度下进行培养。指示剂试验结合伏安法和质谱法将用于检测细菌上清液和细胞微球中的铁载体。这种方法将使我们能够在南极起源和/或其原始栖息地的可培养细菌谱系中区分铁载体类型。我们将通过核磁共振和质谱来阐明新型铁载体的结构，并纯化这些和已知的铁载体，作为定量分析和物理化学特性实验测定的参考标准。一个主要目的是表征不同铁载体类型在典型SO生境条件下的扩散和吸附特性。我们将研究环境参数（温度，盐度）如何影响每种配体类型的铁捕获性能和扩散损失。这些一般的铁载体特征将用于解释细菌生长和铁载体生产依赖于一系列温度、盐度和冰体制的实验结果。这项研究将最终改进现有的细胞铁摄取模型，增加我们对嗜冷细菌铁摄取策略的了解，并最终有助于更好地理解微生物驱动的南极铁循环过程，从而解决DFG SPP呼吁的几个核心标准。