Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Edifici C, Campus de UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain.
Aquat Toxicol. 2013 Sep 15;140-141:324-36. doi: 10.1016/j.aquatox.2013.06.022. Epub 2013 Jul 8.
The roles of consortia of phototrophic microorganisms have been investigated in this paper to determine their potential role to tolerate or resist metals and to capture them from polluted cultures. With this purpose, two consortia of microorganisms: on one hand, Geitlerinema sp. DE2011 (Ge) and Scenedesmus sp. DE2009 (Sc) (both identified in this paper by molecular biology methods) isolated from Ebro Delta microbial mats, and on the other, Spirulina sp. PCC 6313 (Sp) and Chroococcus sp. PCC 9106 (Ch), from Pasteur culture collection were polluted with copper and lead. In order to analyze the ability of these consortia to tolerate and capture metals, copper and lead were selected, because both have been detected in Ebro Delta microbial mats. The tolerance-resistance to copper and lead for both consortia was determined in vivo and at cellular level by Confocal Laser Scanning Microscopy (CLSM-λscan function). The results obtained demonstrate that both consortia are highly tolerant-resistant to lead and that the limits between the copper concentration having cytotoxic effect and that having an essential effect are very close in these microorganisms. The capacity of both consortia to capture extra- and intracellular copper and lead was determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) respectively, coupled to an Energy Dispersive X-ray detector (EDX). The results showed that all the microorganisms assayed were able to capture copper extracellularly in the extrapolymeric substances, and lead extra- and intracellularly in polyphosphate inclusions. Moreover, the studied micro-organisms did not exert any inhibitory effect on each other's metal binding capacity. From the results obtained in this paper, it can be concluded that consortia of phototrophic microorganisms could play a very important role in biorepairing sediments polluted by metals, as a result of their ability to tolerate or resist high concentrations of metals and to bioaccumulate them, extra- and intracellulary.
本文研究了光养微生物联合体的作用，以确定它们耐受或抵抗金属并从受污染的培养物中捕获金属的潜在作用。为此，我们使用了两种微生物联合体：一方面，从埃布罗三角洲微生物垫中分离出的绿藻属 sp. DE2011 (Ge)和栅藻属 sp. DE2009 (Sc)（这两种微生物在本文中均通过分子生物学方法进行了鉴定），另一方面，从巴斯德培养物收藏中分离出的螺旋藻属 sp. PCC 6313 (Sp)和胶球藻属 sp. PCC 9106 (Ch)。用铜和铅污染这些联合体，是因为铜和铅都在埃布罗三角洲微生物垫中被检测到。通过共聚焦激光扫描显微镜 (CLSM-λscan 功能) 在体内和细胞水平上测定了这两种联合体对铜和铅的耐受和捕获能力。结果表明，这两种联合体对铅均具有高耐受和抵抗能力，而且在这些微生物中，具有细胞毒性作用的铜浓度和具有必需作用的铜浓度之间的界限非常接近。通过扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 分别结合能量色散 X 射线探测器 (EDX) 测定了两种联合体捕获细胞外和细胞内铜和铅的能力。结果表明，所有被测试的微生物均能够在外聚合物物质中体外捕获铜，在多磷酸盐包涵体内体外和体内捕获铅。此外，研究中的微生物彼此之间没有抑制对方金属结合能力的作用。从本文的研究结果可以得出结论，光养微生物联合体可以在金属污染沉积物的生物修复中发挥非常重要的作用，因为它们具有耐受或抵抗高浓度金属并将其生物累积的能力，无论是细胞外、细胞内还是细胞内。
