Dorador Cristina, Fink Patrick, Hengst Martha, Icaza Gonzalo, Villalobos Alvaro S, Vejar Drina, Meneses Daniela, Zadjelovic Vinko, Burmann Lisa, Moelzner Jana, Harrod Chris
Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile.
Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Angamos 601, Antofagasta, Chile.
Antonie Van Leeuwenhoek. 2018 Aug;111(8):1361-1374. doi: 10.1007/s10482-018-1091-z. Epub 2018 May 9.
The geological, hydrological and microbiological features of the Salar de Atacama, the most extensive evaporitic sedimentary basin in the Atacama Desert of northern Chile, have been extensively studied. In contrast, relatively little attention has been paid to the composition and roles of microbial communities in hypersaline lakes which are a unique feature in the Salar. In the present study biochemical, chemical and molecular biological tools were used to determine the composition and roles of microbial communities in water, microbial mats and sediments along a marked salinity gradient in Laguna Puilar which is located in the "Los Flamencos" National Reserve. The bacterial communities at the sampling sites were dominated by members of the phyla Bacteroidetes, Chloroflexi, Cyanobacteria and Proteobacteria. Stable isotope and fatty acid analyses revealed marked variability in the composition of microbial mats at different sampling sites both horizontally (at different sites) and vertically (in the different layers). The Laguna Puilar was shown to be a microbially dominated ecosystem in which more than 60% of the fatty acids at particular sites are of bacterial origin. Our pioneering studies also suggest that the energy budgets of avian consumers (three flamingo species) and dominant invertebrates (amphipods and gastropods) use minerals as a source of energy and nutrients. Overall, the results of this study support the view that the Salar de Atacama is a heterogeneous and fragile ecosystem where small changes in environmental conditions may alter the balance of microbial communities with possible consequences at different trophic levels.
阿塔卡马盐沼是智利北部阿塔卡马沙漠中最广阔的蒸发沉积盆地，其地质、水文和微生物特征已得到广泛研究。相比之下，盐沼中独特的高盐湖中微生物群落的组成和作用却相对较少受到关注。在本研究中，利用生化、化学和分子生物学工具，确定了位于“洛斯弗拉门科斯”国家保护区的普拉尔湖沿显著盐度梯度的水体、微生物垫和沉积物中微生物群落的组成和作用。采样点的细菌群落以拟杆菌门、绿弯菌门、蓝细菌门和变形菌门的成员为主。稳定同位素和脂肪酸分析表明，不同采样点的微生物垫组成在水平方向（不同地点）和垂直方向（不同层）均存在显著差异。普拉尔湖被证明是一个以微生物为主导的生态系统，在特定地点超过60%的脂肪酸来自细菌。我们的开创性研究还表明，鸟类消费者（三种火烈鸟物种）和主要无脊椎动物（双壳类和腹足类）的能量预算将矿物质用作能量和营养来源。总体而言，本研究结果支持以下观点：阿塔卡马盐沼是一个异质性且脆弱的生态系统，环境条件的微小变化可能会改变微生物群落的平衡，并可能在不同营养级产生后果。
