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Collection, Isolation and Enrichment of Naturally Occurring Magnetotactic Bacteria from the Environment
Published on: November 15, 2012
Microbial diversity in Calamita ferromagnetic sand
Amedea Perfumo1, Charles Cockell, Andreas Elsaesser
1Planetary Protection, European Space Agency-ESA/ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands School of Biomedical Sciences, University of Ulster, Coleraine, UK Planetary and Space Science Research Institute, Open University, Milton Keynes, UK.
Environmental Microbiology Reports
|June 14, 2013
Summary
Researchers characterized Calamita sand, an iron-rich marine environment. They discovered low bacterial biodiversity, dominated by radiation- and desiccation-tolerant microbes, expanding knowledge of extreme environments.
Area of Science:
- Geomicrobiology
- Environmental microbiology
- Extremophile research
Background:
- Calamita sand is a marine iron ore deposit on Elba Island, Italy.
- It features high iron content (approx. 80%) with significant magnetic properties (63% w/w).
- Extreme conditions include desiccation, UV irradiation, and high temperatures due to iron's thermal conductivity.
Purpose of the Study:
- To conduct the first geomicrobiological characterization of Calamita sand.
- To identify bacterial biodiversity and community structure in this extreme environment.
- To understand the biogeographical distribution of extremotolerant organisms.
Main Methods:
- Denaturing gradient gel electrophoresis (DGGE) for bacterial community analysis.
- 16S rRNA gene clone library analysis for sequence identification.
- Cultivation of thermophilic bacteria at 60°C.
Main Results:
- Low bacterial biodiversity was observed in Calamita sand.
- The dominant bacteria belonged to phyla Proteobacteria, Actinobacteria, and Deinococcus-Thermus, showing radiation and desiccation tolerance.
- Abundant heavy metal-resistant organisms like Variovorax sp. and lithotrophic iron oxidizers were detected.
- Thermophilic bacilli were successfully cultivated at 60°C.
Conclusions:
- Calamita sand harbors a unique microbial community adapted to harsh, iron-rich conditions.
- The findings reveal similarities to bacteria found in extreme deserts.
- This study enhances understanding of biodiversity in extreme iron-rich biotopes and their biogeography in the Mediterranean.
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