Microbes Found in the Sky

In the article "Microbes Survive, and Maybe Thrive, High in the Atmosphere" by Lizzie Wake in Science Now (http://news.sciencemag.org/sciencenow/2013/01/microbes-survive-and-maybe-thriv.html) talks about the microbes that can live in the middle to upper troposphere.

In January 2013, a group of scientists from Georgia Institute of Technology in Atlanta took air samples from NASA airplanes that were studying hurricanes. These scientists collected thousands of samples from 10 kilometer above sea level around the United States.

The scientists counted 5,200 bacterial cells per cubic meter of air and found that 60% of the bacteria were alive. Some of the bacteria in the atmosphere feed on oxalic acid, which is one of the most abundant chemicals in the sky. Out of all these bacterial cells, there were 314 different families. However, the scientists were not able to determine the species of the bacteria and if any of them were pathogens.

These microbes are brought to the sky by storms like hurricanes or tornadoes. A microbiologist named Dale Griffin explained that "storms serve as an atmospheric escalator plucking dirt, dust, seawater, and, now, microbes off the earth's surface and carrying them high into the sky." This quote explains why there are so many microbes in the sky and how they are getting there.

There is a possibility that there might be an ecosystem in the atmosphere. Microbes in the sky can also affect the weather, they happen to be the perfect size and texture to form clouds.This may result in precipitation such as rain.

In my opinion, I do not believe that microbes affect the weather as much as scientists think they do. In theory, after one storm, the microbes that are in the sky would form clouds and those clouds may create another storm. If this continues, everyday would be stormy.  In reality, you can't see how the microbes are affecting the weather. Not every microbe ends up becoming a cloud. So microbes would affect the weather less than scientists think.

This article makes me think about the cytology unit. The metabolic activity for eukaryotes and prokaryotes are either aerobic or anaerobic respiration. The amount of oxygen available decreases as the altitude increases. Thus aerobic respiration becomes less effective, and anaerobic bacteria would also function in the presence of low oxygen. The bacteria that survive in these environments either aerobically respire or use oxalic acid for energy.

Image: http://news.sciencemag.org/sciencenow/assets/2013/01/28/sn-atmosphere.jpg