Cryo-micro-Raman spectroscopy and next generation sequencing for investigation of biomarkers in water ice inclusions of the subglacial antarctic lake

冷冻显微拉曼光谱和下一代测序用于研究南极冰下湖水冰包裹体中的生物标志物

• 批准号: 429811207
• 负责人: Professor Dr. Heinz-Wilhelm Hübers
• 金额: --
• 依托单位: Institut für Physik
• 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/429811207?language=en
• 关键词: Cryo; micro; Raman; spectroscopy; next

The aim of the project is to discover Lake Vostok inhabiting microorganisms, extant or extinct. The scientific potential of cryo Raman microscopy and Next Generation Sequencing (NGS) for accurate detection and identification of specific biogenic markers will be evaluated and applied for identification of organic-matter related substances in the water ice cores obtained from the subglacial Antarctic Lake Vostok. Two consequent analytical techniques will be applied to the icy samples, first without their melting and after that on the melted products. First, micro-Raman spectroscopy will enable contactless localization and identification of organic matter related substances, preventing contamination and evaporation of material entrapped in an ice matrix, solid and gaseous. Raman spectroscopy will be applied on both natural as well as artificial ice samples, and later on solid inclusions recovered from the Lake Vostok ice. The organic carbon, lipids and proteins as DNA proxy have been selected as probable specific biomarkers for Raman spectroscopy for these pristine samples with very rare solid and some volatile gas inclusions. The limits of detection for the artificial biomarker-ice samples will be determined in the frame of the project. Given a positive feedback the ice can be melted in the laboratory under clean room conditions and a solid inclusion (along with the local melt) can be reinvestigated by Raman spectroscopy along with complementary biogeochemical methods. The PCR followed by Next Generation Sequencing of extracted microbial genomic DNA along with complementary analyses (microparticle counting, SEM and AFM, organic carbon content, analytical water chemistry, cell concentration counting) will be used for the post-treated samples. The PCR and NGS sequencing will allow proving the Raman results and discover Lake Vostok inhabiting microorganisms, extant or extinct. The research will have impact on space research and astrobiology. Space missions with payloads for in-situ planetary exploration (e.g. Raman spectrometers) will search for life on Solar system bodies with oceans which are covered by ice crusts are somewhat comparable to the Lake Vostok. The search for extant or extinct extraterrestrial life as a main goal of astrobiology is based on revealing and characterization of biomarkers. The main objects to search for such life signatures are icy moons and planets featured by polar ice caps, e.g. frozen-water-rich subsurface permafrost on Mars and ice-covered oceans on Jupiter’s Europa and Saturn’s Enceladus. The samples to study are expected to be water ice containing different inclusions embedded into a tough crystalline lattice permeable for light gases (helium, hydrogen) only. The subglacial Antarctic Lake Vostok serves as a unique terrestrial analogue. The project aims to strengthen the European international cooperation between research groups actively participating in polar region research and in space research/astrobiology.

该项目的目的是发现居住在沃斯托克湖中的现存或灭绝的微生物。将评估冷冻拉曼显微镜和下一代测序（NGS）在准确检测和鉴定特定生物标记方面的科学潜力，并将其应用于有机物的鉴定。从冰下南极沃斯托克湖获得的水冰芯中的物质相关物质将应用于冰样品，首先是不融化和分析。首先，微拉曼光谱将实现有机物相关物质的非接触式定位和识别，防止冰基质中截留的物质的污染和蒸发，固体和气体拉曼光谱将应用于天然物质。以及人造冰样本，以及后来从沃斯托克湖冰中回收的固体包裹体，作为 DNA 代表的有机碳、脂质和蛋白质已被选为这些原始拉曼光谱的可能特异性生物标志物。含有非常罕见的固体和一些挥发性气体夹杂物的样品将在该项目的框架内确定，如果得到积极的反馈，冰可以在洁净室条件下融化。固体夹杂物（以及局部熔化）可以通过拉曼光谱以及补充的生物地球化学方法重新研究，然后对提取的微生物基因组 DNA 进行下一代测序以及补充分析（微粒计数、SEM 和 AFM、有机碳含量、 PCR和NGS测序将用于验证拉曼结果并发现沃斯托克湖中现存或灭绝的微生物。具有原位行星探索有效载荷的太空任务（例如拉曼光谱仪）将在被冰壳覆盖的海洋（类似于湖泊）的太阳系天体上寻找生命。寻找现存或灭绝的外星生命作为天体生物学的主要目标是基于生物标记的揭示和表征，寻找此类生命特征的主要对象是具有极地冰盖的冰卫星和行星，例如冰冻的水。火星上丰富的地下永久冻土以及木星欧罗巴和土星土卫二上冰覆盖的海洋预计要研究的样本是含有不同成分的水冰。嵌入仅可渗透轻气体（氦气、氢气）的坚韧晶格中的夹杂物南极冰下沃斯托克湖是一个独特的陆地类似物，该项目旨在加强积极参与极地研究的研究小组之间的国际合作。空间研究/天体生物学。