Living organisms on Earth, just find spaces or impossible conditions.They are in extreme environments, whether deep underwater vents, polar ice or toxic chemical environments, on land and at sea. And now in the air, a high altitude. Scientists have found large amounts of bacteria and fungi in the atmosphere, between 8 and 15 miles high, where they constitute up to 20% of what was previously thought to be simply grains of powder and salt. Samples were taken in the middle and upper troposphere over the Caribbean and parts of the Atlantic, with a reconnaissance aircraft overflights during two hurricanes.
There are also fungi and scientists above based on the assumption that the origin of organisms on the surface and are carried by high winds.What we do not know yet is if adapted to live in the middle of feeding air carbon compounds. “We did not expect to find so many microorganisms in the troposphere, which is considered a difficult environment for life,” said Kostas Konstantinidis ( Georgia Institute of Technology in Atlanta,USA). So far, scientists have found that in all samples taken are types of bacteria that are known to live in certain carbon compounds, “indicating that these organisms have characteristics that allow them to survive in the troposphere,” adds researcher.
The presence of these microorganisms in the air at that altitude can have substantial impact on the climate and weather, they can act asseeds for the formation of ice and water drops, with the consequent impact on the water cycle, clouds and climate. Furthermore, the study of the transport of bacteria and fungi in the air is useful to outline the geographical patterns of disease transmission, experts emphasize the journal Proceedings of the National Academy of Sciences (USA) , which discloses research led by Natasha Leon-Rodriguez.
Using special filters, a plane of NASA was taking air samples before, during and after the huracanares Earl and Karl, in 2010, in its research program of air masses at high altitude during tropical storms. The flights were conducted on land and on sea, with clouds and cloudless.Scientists then applied in laboratory Atlanta advanced techniques of genetic sequencing to detect the presence of microorganisms and estimating the quantity without resorting to conventional processes and slow cell culture.
Germs can live carbon compounds in the air
“Microbial communities tropospheric high and air masses on marine and oceanic regions barely known” because of the difficulty in obtaining significant samples, the researchers write in Proceedings. “Little is known of its composition, spatial distribution and variability temporary, and its ability to adapt to the environment “, continue. It is also unclear whether they can metabolize the organic compounds in the atmosphere.
For now, what De Leon-Rodriguez and colleagues have seen is that the proportion of marine bacteria is higher in air masses originating over the ocean, while land predominate in the air from the ground.Microorganisms must originate from the planet’s surface, and the question is whether, once in the stratosphere, are adapted to live there.What is clear is that hurricanes have a major impact on the distribution and dynamics of these populations. Bacteria samples of 17 different big groups are far more numerous than the fungi.
Until now, it had advanced molecular studies of samples from mountain summits in the air near the surface and snowflakes, remind researchers.But the scope of this new sampling intense air filters on a plane in flight and avoiding contamination of catches and applied genetic analysis, are a big step forward. In total, NASA flights provided samples taken during a flight the California coast, another from there to mainland Florida and seven flights in the Gulf of Mexico environment dedicated to hurricanes.
Quantitative techniques of DNA amplification reaction (polymerase chain PCR) and microscopic counts have established that viable bacterial cells represent approximately one fifth of all particles of size between 0.25 micron and present in tropospheric samples.
Scientists have applied DNA analysis to counts
The next step of the investigation will determine whether some types of bacteria are more likely than others to survive in the air so high. Scientists also want to determine if they have metabolic functions up there. “For these conditions bodies may not be as hard” Konstantinidis said. “I would not be surprised if there were life and biological growth in the clouds.”