[Microorganisms of the upper layers of the atmosphere]

Samples for microbiological studies were taken at a high altitude using meterological rockets with specially constructed analyzers so that no extraneous microorganisms could get into them before sampling. The analyzers were sterilized by gamma-irradiation before sampling. For the first time, microscopic fungi, bacteria and mycobacteria were detected at a height of 48--77 km. Five among six of the microbial species were found to contain pigments. The prevalence of these forms at high altitudes suggests that natural selection may take place in the upper atmospheric layer since cells containing chromogenic pigments (carotenoids, melanins) are more resistant to the action of ultraviolet rays.