Unravelling the formation of unique modern stromatolites by taxonomic and functional analysis: implications for the early evolution of life

通过分类学和功能分析揭示独特的现代叠层石的形成：对生命早期进化的影响

• 批准号: EP/X024873/1
• 负责人: Lara Vimercati
• 金额: $ 24.26万
• 依托单位: Natural History Museum
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX024873%2F1
• 关键词: Unravelling; formation; unique; modern; stromatolites

Lake Untersee in East Antarctica represents a unique ice-sealed ecosystem with ultra-oligotrophic waters, high pH and it is tightly sealed from the environment except for the penetration of sunlight (5%). This habitat serves as an ecological analog of early Earth and other worlds in our solar system characterized by thick permanent ice covers, such as Enceladus, Europa and ancient ice-covered lakes on Mars. It is the only known freshwater lake hosting large conical modern stromatolites at its bottom. These structures consist of a thin layer of oxygenic photosynthetic Bacteria covering alternating laminations of sediment and microbially derived organic matter. It is still unknown why these large conical stromatolites occur exclusively at this site. I propose to use an integrative approach to determine taxonomy and functionality of these structures to shed light on the mechanisms driving their formation. Investigations to understand the microbial assemblages as well as functional potential of communities will be done using in-depth environmental taxonomic, metagenomic and imaging analyses. This research will investigate the role played by Bacteria, Eukarya and Archaea in the formation of conical stromatolites as well as understanding whether these structures are characterized by a core taxonomy and functionality. Microbiome composition and function of the stromatolites of Lake Untersee will be compared with that of microbial structures in similar Antarctic lakes to understand the effect of environment and geography. SEM and confocal laser scanning will be used to explore physical interactions between microbes and minerals in conical stromatolites and to provide information on the biogeochemical processes involved. This research will advance our knowledge on the emergence of complex structures in microbial mats and is fundamental to interpret biological influences on ancient stromatolites.

南极洲东部的Untersee湖代表了一个独特的冰封生态系统，具有超贫营养沃茨，高pH值，除了阳光的渗透（5%）外，它与环境紧密密封。这个栖息地是早期地球和太阳系其他世界的生态模拟，其特征是厚厚的永久冰层，如土卫二，欧罗巴和火星上古老的冰层覆盖的湖泊。它是唯一已知的淡水湖托管大型圆锥形现代叠层石在其底部。这些结构由一层薄薄的光合细菌组成，覆盖着沉积物和微生物衍生的有机物的交替层。目前还不清楚为什么这些大型圆锥形叠层石只发生在这个地点。我建议使用一种综合的方法来确定这些结构的分类和功能，以阐明驱动其形成的机制。将利用深入的环境分类学、宏基因组学和成像分析进行调查，以了解微生物组合以及群落的功能潜力。这项研究将调查细菌，真核生物和真菌在圆锥形叠层石形成中所起的作用，并了解这些结构是否具有核心分类学和功能。Untersee湖的微生物组成和功能将与南极类似湖泊的微生物结构进行比较，以了解环境和地理的影响。扫描电镜和共聚焦激光扫描将用于探索微生物和矿物之间的物理相互作用，在锥形叠层石，并提供有关的地球化学过程的信息。这项研究将推进我们对微生物垫中复杂结构的出现的认识，并且对于解释生物学对古代叠层石的影响至关重要。