The detection of biosignatures on Mars is of outstanding interest in the current field of astrobiology and drives various fields of research, ranging from new sample collection strategies to the development of more sensitive detection techniques. Detailed analysis of the organic content in Mars analog materials collected from extreme environments on Earth improves the current understanding of biosignature preservation and detection under conditions similar to those of Mars. In this article, we examined the biological fingerprint of several locations in the Atacama Desert (Chile), which include different wet and dry, and intermediate to high elevation salt flats (also named salars). Liquid chromatography and multidimensional gas chromatography mass spectrometry measurement techniques were used for the detection and analysis of amino acids extracted from the salt crusts and sediments by using sophisticated extraction procedures. Illumina 16S amplicon sequencing was used for the identification of microbial communities associated with the different sample locations. Although amino acid load and organic carbon and nitrogen quantities were generally low, it was found that most of the samples harbored complex and versatile microbial communities, which were dominated by (extremely) halophilic microorganisms (most notably by species of the Archaeal family Halobacteriaceae). The dominance of salts (i.e., halites and sulfates) in the investigated samples leaves its mark on the composition of the microbial communities but does not appear to hinder the potential of life to flourish since it can clearly adapt to the higher concentrations. Although the Atacama Desert is one of the driest and harshest environments on Earth, it is shown that there are still sub-locations where life is able to maintain a foothold, and, as such, salt flats could be considered as interesting targets for future life exploration missions on Mars.

中文翻译：

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来自阿塔卡马沙漠的火星土壤类似物的生物特征分析：未来火星任务的挑战和启示。

火星上生物特征的检测在当前的天体生物学领域中引起了极大的兴趣，并推动了各个领域的研究，从新的样本收集策略到更敏感的检测技术的发展。对从地球上的极端环境收集的火星模拟材料中有机物含量的详细分析，增进了对与火星相似条件下生物特征保存和检测的当前理解。在本文中，我们检查了阿塔卡马沙漠（智利）几个地点的生物指纹，包括不同的湿，干以及中高海拔盐沼（也称为撒拉族）。液相色谱法和多维气相色谱质谱法测量技术用于通过复杂的提取程序检测和分析从盐皮和沉积物中提取的氨基酸。Illumina 16S扩增子测序用于鉴定与不同样品位置相关的微生物群落。尽管氨基酸负载量和有机碳和氮含量通常较低，但发现大多数样品都具有复杂而通用的微生物群落，这些群落主要由（极端）嗜盐微生物（主要是古细菌家族的物种）主导 Illumina 16S扩增子测序用于鉴定与不同样品位置相关的微生物群落。尽管氨基酸负载量和有机碳和氮含量通常较低，但发现大多数样品都具有复杂而通用的微生物群落，这些群落主要由（极端）嗜盐微生物（主要是古细菌家族的物种）主导 Illumina 16S扩增子测序用于鉴定与不同样品位置相关的微生物群落。尽管氨基酸负载量和有机碳和氮含量通常较低，但发现大多数样品都具有复杂且用途广泛的微生物群落，这些群落主要由（极端）嗜盐微生物（主要是古细菌家族的物种）主导盐杆菌科）。被调查样品中盐（即卤石和硫酸盐）的优势在微生物群落的组成上留下了印记，但由于它显然可以适应更高的浓度，因此似乎并未阻碍生命的蓬勃发展。尽管阿塔卡马沙漠是地球上最干旱和最恶劣的环境之一，但事实表明，仍有一些子区域可以维持生命的立足点，因此盐滩可被视为未来生活的有趣目标火星探索任务。