Departamento de Metagenómica, Fundación Bionostra Chile Research, San Miguel, Santiago, Chile.
Laboratory of Bioenergy and Environmental Biotechnology, Department of Environmental Sciences and Natural Resources, Faculty of Agricultural Sciences, University of Chile, La Pintana, Santiago, Chile.
Microbiol Spectr. 2023 Jun 15;11(3):e0520022. doi: 10.1128/spectrum.05200-22. Epub 2023 Apr 27.
The lacustrine systems of La Brava and La Punta, located in the Tilopozo sector in the extreme south of Salar de Atacama, are pristine high-altitude Andean lakes found along the central Andes of South America. This shallow ecosystem suffers from permanent evaporation, leading to falling water levels, causing it to recede or disappear during the dry season. This dynamic causes physicochemical changes in lakes, such as low nutrient availability, pH change, and dissolved metals, which can influence the composition of the microbial community. In this study, we used a metataxonomic approach (16S rRNA hypervariable regions V3 to V4) to characterize the sedimentary microbiota of these lakes. To understand how the water column affects and is structured in the microbiota of these lakes, we combined the analysis of the persistence of the water column through satellite images and physicochemical characterization. Our results show a significant difference in abiotic factors and microbiota composition between La Punta and La Brava lakes. In addition, microbiota analysis revealed compositional changes in the ecological disaggregation (main and isolated bodies) and antagonistic changes in the abundance of certain taxa between lakes. These findings are an invaluable resource for understanding the microbiological diversity of high Andean lakes using a multidisciplinary approach that evaluates the microbiota behavior in response to abiotic factors. In this study, we analyzed the persistence of the water column through satellite images and physicochemical characterization to investigate the composition and diversity in High Andean Lake Systems in a hyperarid environment. In addition to the persistence of the water column, this approach can be used to analyze changes in the morphology of saline accumulations and persistence of snow or ice; for example, for establishing variable plant cover over time and evaluating the microbiota associated with soils with seasonal changes in plants. This makes it an ideal approach to search for novel extremophilic microorganisms with unique properties. In our case, it was used to study microorganisms capable of resisting desiccation and water restriction for a considerable period and adapting to survive in ecological niches, such as those with high UV irradiation, extreme drought, and high salt concentration.
拉布拉瓦湖（La Brava）和拉彭塔湖（La Punta）位于阿塔卡马盐沼（Salar de Atacama）最南端的蒂洛波佐（Tilopozo）扇区，是沿着南美洲安第斯山脉中心发现的原始高海拔安第斯高山湖泊。这个浅生态系统遭受着永久性蒸发的影响，导致水位下降，在旱季时会退缩或消失。这种动态变化导致湖泊发生理化变化，例如营养物质可用性降低、pH 值变化和溶解金属等，这可能会影响微生物群落的组成。在这项研究中，我们使用了一种分类组学方法（16S rRNA 高变区 V3 到 V4）来描述这些湖泊的沉积微生物群。为了了解水柱如何影响这些湖泊的微生物群并对其进行结构构建，我们结合卫星图像和理化特性分析来研究水柱的持久性。我们的结果表明，拉彭塔湖（La Punta）和拉布拉瓦湖（La Brava）的非生物因素和微生物群落组成存在显著差异。此外，微生物群落分析显示，在生态解体（主和孤立体）方面存在组成变化，并且在湖泊之间某些分类群的丰度上存在拮抗变化。这些发现为使用多学科方法评估微生物群对非生物因素的反应行为，从而了解高安第斯山脉湖泊的微生物多样性提供了宝贵的资源。在这项研究中，我们通过卫星图像和理化特性分析来研究高海拔安第斯湖泊系统在极端干旱环境中的组成和多样性，以了解水柱的持久性。除了水柱的持久性外，这种方法还可以用于分析盐类积聚形态的变化以及积雪或冰的持久性；例如，用于随时间建立可变的植物覆盖，评估与土壤相关的微生物群，这些土壤的植物会随着季节变化而变化。这使其成为寻找具有独特特性的新型极端微生物的理想方法。在我们的案例中，它被用于研究能够抵抗相当长时间的干燥和水分限制并适应在生态位中生存的微生物，例如那些具有高 UV 辐射、极端干旱和高盐浓度的生态位。
