JoNova

File this under: “How little we know.”

The upper troposphere is apparently teeming with particles of bacteria and fungi, surprising researchers.* Proving that life is tenacious and that microbes can survive just about anywhere, a team at Georgia Institute of Technology have discovered that quite a bit of what we assumed was dust and sea-salt may be bacteria aloft. Some of the little critters made it as high as the upper troposphere which is 10km up (where commercial flights cruise). No one is quite sure if the microbes “live” up there, or were just visiting.

The study showed that viable bacterial cells represented, on average, around 20 percent of the total particles detected in the size range of 0.25 to 1 microns in diameter. By at least one order of magnitude, bacteria outnumbered fungi in the samples, and the researchers detected 17 different bacteria taxa – including some that are capable of metabolizing the carbon compounds that are ubiquitous in the atmosphere – such as oxalic acid.

The bacteria were probably tossed up there by wind and waves:

When the air masses studied originated over the ocean, the sampling found mostly marine bacteria. Air masses that originated over land had […]