Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA.
The Natural History Museum, London, UK.
Astrobiology. 2023 Sep;23(9):1006-1018. doi: 10.1089/ast.2022.0155. Epub 2023 Aug 11.
Permafrost is important from an exobiology and climate change perspective. It serves as an analog for extraplanetary exploration, and it threatens to emit globally significant amounts of greenhouse gases as it thaws due to climate change. Viable microbes survive in Earth's permafrost, slowly metabolizing and transforming organic matter through geologic time. Ancient permafrost microbial communities represent a crucial resource for gaining novel insights into survival strategies adopted by extremotolerant organisms in extraplanetary analogs. We present a proof-of-concept study on ∼22 Kya permafrost to determine the potential for coupling Raman and fluorescence biosignature detection technology from the NASA Mars Perseverance rover with microbial community characterization in frozen soils, which could be expanded to other Earth and off-Earth locations. Besides the well-known utility for biosignature detection and identification, our results indicate that spectral mapping of permafrost could be used to rapidly characterize organic carbon characteristics. Coupled with microbial community analyses, this method has the potential to enhance our understanding of carbon degradation and emissions in thawing permafrost. Further, spectroscopy can be accomplished to mitigate sample transport challenges and in assessing and prioritizing frozen soils for further investigation. This method has broad-range applicability to understanding microbial communities and their associations with biosignatures and soil carbon and mineralogic characteristics relevant to climate science and astrobiology.
从天体生物学和气候变化的角度来看，永冻土很重要。它是行星际探索的模拟物，由于气候变化，它有可能解冻并释放出大量对全球有重大影响的温室气体。在地球的永冻土中，存活的微生物通过地质时间缓慢地代谢和转化有机物质。古代永冻土微生物群落代表了一个重要的资源，可以深入了解在行星际模拟物中极端耐受生物所采用的生存策略。我们提出了一项关于约 22 千年前永冻土的概念验证研究，以确定从美国宇航局火星毅力号探测器中拉曼和荧光生物特征检测技术与冷冻土壤中微生物群落特征相结合的可能性，这一技术可以扩展到其他地球和地外地点。除了众所周知的生物特征检测和识别的用途外，我们的结果还表明，永冻土的光谱测绘可用于快速表征有机碳特征。结合微生物群落分析，这种方法有可能增强我们对解冻永冻土中碳降解和排放的理解。此外，光谱学可以完成缓解样本运输挑战，并评估和优先考虑进一步调查的冷冻土壤。这种方法具有广泛的适用性，可以帮助我们了解微生物群落及其与生物特征以及与气候科学和天体生物学相关的土壤碳和矿物学特征的关联。
