This article here makes me think it's probably something much more theoretical (and thus, less exciting) than space bacteria or amino acids or whatever.
http://nasawatch.com/archives/2010/11/mediablogger-ex.html
Cue the sadface of pandas and lost kittens.
http://nasawatch.com/archives/2010/11/mediablogger-ex.html
Cue the sadface of pandas and lost kittens.