Could some bacteria theoretically evolve to survive in space? There is no edge to the atmosphere, and therefor I expect there would be a gradual reduction of concentrations of bacteria as we ascend into space. Logically anaerobic bacteria should be able to obtain its energy from the sun and nutrients from whatever scarce but available organic floating materials. Cosmic rays and high energy particles could damage DNA, but there might be someway life could protect itself against them. Could it be that bacteria is evolving/ has already evolved at the edge of the atmosphere to live in space?
Currently there is no life that we know of that evolved in, or can survive for prolonged time in a vacuum.

To say 'Life in space is possible because there is anaerobic life' is a completely wrong point, that ignores the effects of vacuum on life.

Sure, there are extremophiles that can survive for a limited time in space (see also this list) when going into hibernation modes. However all life as we know it needs liquids and/or gases to survive. Those would evaporate once the cell/water bear would become active again. Activity is necessary to sustain and multiply life, so no, nothing that we know of can stay active and alive in space.


  Cosmic rays and high energy particles could damage DNA, but there might be someway life could protect itself against them


Until life comes up with such mechanisms, we just don't know. The problems with liquids and gases evaporating would need some tougher solutions even.

Bacteria are also pretty heavy 'particles' and therefore cannot float anywhere near the 'edge of space'. There are reports of bacteria in the stratosphere, but that requires already strong upwinds to put them there.