**9. Conclusions**

Intense UV radiation, low pressure, lack of water and nutrients, and freezing temperatures turn the atmosphere into an extreme environment, especially its upper layers. However, it is widely known that airborne bacteria, fungal spores, pollen, and other bioparticles exist. Numerous bacteria and fungi have been isolated and can survive even at stratospheric altitudes. Microbial survival in the atmosphere requires extremophilic characteristics, and therefore airborne microbiota is potentially useful for biotechnological applications. The role of airborne microbial communities is vital in the Earth, including interactions among the atmosphere, biosphere, climate, and public health. Airborne microorganisms are involved in meteorological processes and can serve as nuclei for cloud drops and ice crystals that precede precipitation, which influences the hydrological cycle and climate. Furthermore, their knowledge is essential in understanding the reproduction and propagation of organisms through various ecosystems. Furthermore, they can cause or improve human, animal, and plant diseases.

**55**

provided the original work is properly cited.

Technology, Torrejón de Ardoz, Spain

*Microbial Ecology in the Atmosphere: The Last Extreme Environment*

Airborne platforms that allow conducting a direct study of microorganisms in the atmosphere and molecular methodologies (e.g., "omics") could represent a major opportunity for approaching this question. Nevertheless, some challenges must yet be solved, such as low biomass, efficiency of sampling methods, the absence of

Deserts and arid lands are one of the most important sources of aerosol emissions. Clouds of dust generated by storms mobilize tons of mineral particles, and it is known that microorganisms remain attached to the particles being transported over long distances. The large number of mineral particles and microorganisms thus placed into the atmosphere has global implications for climate, biochemical cycling, and health. North African soils, primarily the Sahara Desert, are one of the major sources of airborne dust on Earth. Saharan dust is often transported to southern Europe and could even reach high altitudes over the Atlantic Ocean and the European continent. Again, airborne platforms could be a perfect opportunity

This work has been supported by grants from the Spanish government (www. mineco.gob.es and www.csic.es) (CGL2015-69758-P and i-LINK1151). Publishing

standard protocols, or the high variability of the atmospheric environment.

for conducting a direct study of the microbiology of this kind of events.

*DOI: http://dx.doi.org/10.5772/intechopen.81650*

**Acknowledgements**

**Author details**

Ángeles Aguilera1

Suthyvann Sor Mendi<sup>2</sup>

Torrejón de Ardoz, Spain

fee has been has been supported by Open Access.

, Graciela de Diego-Castilla1

, Yolanda Blanco1

\*Address all correspondence to: gonzalezte@cab.inta-csic.es

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Astrobiology Institute (INTA-CSIC), National Institute for Aerospace Technology,

2 Department of Aerodynamics and Propulsion, National Institute for Aerospace

, Susana Osuna1

and Elena González-Toril1

, Rafael Bardera2

\*

,

*Microbial Ecology in the Atmosphere: The Last Extreme Environment DOI: http://dx.doi.org/10.5772/intechopen.81650*

Airborne platforms that allow conducting a direct study of microorganisms in the atmosphere and molecular methodologies (e.g., "omics") could represent a major opportunity for approaching this question. Nevertheless, some challenges must yet be solved, such as low biomass, efficiency of sampling methods, the absence of standard protocols, or the high variability of the atmospheric environment.

Deserts and arid lands are one of the most important sources of aerosol emissions. Clouds of dust generated by storms mobilize tons of mineral particles, and it is known that microorganisms remain attached to the particles being transported over long distances. The large number of mineral particles and microorganisms thus placed into the atmosphere has global implications for climate, biochemical cycling, and health. North African soils, primarily the Sahara Desert, are one of the major sources of airborne dust on Earth. Saharan dust is often transported to southern Europe and could even reach high altitudes over the Atlantic Ocean and the European continent. Again, airborne platforms could be a perfect opportunity for conducting a direct study of the microbiology of this kind of events.
