کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4436232 1310670 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Microbial diversity of the 180 million-year-old Toarcian argillite from Tournemire, France
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Microbial diversity of the 180 million-year-old Toarcian argillite from Tournemire, France
چکیده انگلیسی

Even though the microbiology of various subsurface environments has been investigated for more than 30 a, the microbial diversity of deep argillaceous media is still poorly known. In the context of radioactive waste disposal in clayey formations, the consequence of microbial activity is of concern regarding e.g. the corrosion of metallic components. The purpose of the present work was to characterise the cultivable microbial diversity of different zones of the Toarcian argillite of Tournemire (France) as a preliminary indication regarding the potential of development of microbes in such subterrestrial environments. Cores were drilled in the Excavation Damaged Zone (EDZ) and in the deeper undisturbed zone of the argillite layer, as well as in a zone intersected by a geological fault. Samples from the wall of the drift were also collected. Microorganisms were cultivated from all samples, but the biodiversity differed depending mainly on the O2 and moisture content. Aerobic bacteria were identified on the wall, in the EDZ and in the wet faulted area, whereas SO4-reducing bacteria were isolated from the wet faulted area only. Anaerobic heterotrophs were cultivated from all zones. One hundred and twelve isolates were identified. Small ribosomal subunit gene sequences showed that bacteria of the undisturbed zone were affiliated to three genera only, whereas the three other sampled zones harbour more diverse microflora, including isolates closely related to taxons characterized from subsurface, deep marine and polar environments.


► The cultivable microbial diversity of the argillite of Tournemire was characterized.
► The biodiversity of the undisturbed argillite is limited to three Gram-positive genera.
► That of EDZ differed, depending mainly on oxygen availability and moisture content.
► The overall metabolic diversity is limited to a few trophic groups.
► All attempts of DNA extraction for molecular approaches failed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Geochemistry - Volume 27, Issue 7, July 2012, Pages 1442–1450
نویسندگان
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