de los Ríos Asunción, Wierzchos Jacek, Sancho Leopoldo G, Ascaso Carmen
Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Cientificas, Serrano 115 bis, Madrid, Spain.
FEMS Microbiol Ecol. 2004 Nov 1;50(3):143-52. doi: 10.1016/j.femsec.2004.06.010.
In this microscopy study, we show that microorganisms comprising many endolithic communities of the McMurdo Dry Valleys of Antarctica appear in different physiological states. Live/dead microbial fluorescence stains were used to identify the state of microorganisms in the biofilms. The ultrastructures of these microorganisms were then characterized by transmission electron microscopy. Cyanobacteria were associated with heterotrophic bacterial cells, while fungal cells were free-living or formed partners with green alga as lichens. The extracellular polymeric substances, in which the endolithic microorganisms were embedded, formed an integral part of the biofilms observed. Extracellular polymeric substances probably play a significant role in nutrient interactions and protection of microorganisms from the environmental conditions outside the film. Living, moribund, dormant and dead microorganisms shared this microhabitat. The ecological impacts of the observed physiological dynamics are discussed.
在这项显微镜研究中，我们发现，构成南极洲麦克默多干谷许多石内群落的微生物呈现出不同的生理状态。利用活/死微生物荧光染色来鉴定生物膜中微生物的状态。然后通过透射电子显微镜对这些微生物的超微结构进行了表征。蓝细菌与异养细菌细胞相关联，而真菌细胞则为自由生活状态，或与绿藻形成地衣共生体。石内微生物所嵌入的细胞外聚合物是观察到的生物膜的一个组成部分。细胞外聚合物可能在营养物质相互作用以及保护微生物免受膜外环境条件影响方面发挥着重要作用。活的、濒死的、休眠的和死亡的微生物共享这一微生境。文中讨论了所观察到的生理动态的生态影响。
