Prokaryotic community composition and ecology of floating macroscopic filaments from an extreme acidic environment, Río Tinto (SW, Spain)

• Published in: Systematic and applied microbiology 2007-12, Vol.30 (8), p.601-614
• Main Authors: García-Moyano, A., González-Toril, E., Aguilera, A., Amils, R.
• Format: Article
• Language: English
• Subjects: Acidiphilium; Acidithiobacillus ferrooxidans; Acidophiles; Acinetobacter; Aeromonas; Animal, plant and microbial ecology; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Biodiversity; Biological and medical sciences; Clostridium; DNA Fingerprinting; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Bacterial - isolation & purification; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Electrophoresis, Polyacrylamide Gel; Extremophiles; Freshwater; Fundamental and applied biological sciences. Psychology; Genes, rRNA; In Situ Hybridization, Fluorescence; Leptospirillum ferrooxidans; Macroscopic filaments; Microbial ecology; Molecular ecology; Molecular Sequence Data; Mycobacterium; Nucleic Acid Denaturation; Phylogeny; Rivers - microbiology; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Río Tinto; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Spain; Various environments (extraatmospheric space, air, water)
• ISSN: 0723-2020; 1618-0984
• DOI: 10.1016/j.syapm.2007.08.002

The prokaryotic diversity of macroscopic filaments located at the water surface in an extreme acidic environment, Río Tinto (SW, Spain), has been analysed through denaturing gradient gel electrophoresis (DGGE), cloning of 16S rRNA genes and fluorescence in situ hybridization (FISH). The dominant species present in the macrofilaments were Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans and Acidiphilium spp., which represented the three main bacterial genera found in the water column of the river. However, our results also showed the presence of other microorganisms not previously detected in the Río Tinto. Within the Gammaproteobacteria class, sequences closely related to the iron-oxidizing bacteria WJ2 and DSM 2392 were found, as well as sequences related to the non-acidophilic genera Aeromonas and Acinetobacter. In addition, two other new phylotypes related to Gram-positive species from the genera Desulfosporosinus, Clostridium and Mycobacterium were identified. The presence of these anaerobic microorganisms strongly suggests that the filaments could originate in the deeper parts of the river as a typical acid streamer attached to the rocks or the sediments and be pulled up towards the surface when they reach certain buoyancy.