2 Daria Morozova 2007 Tolerance limits and survival potential of methanogenic archaea from Siberian permafrost under extreme living conditions Potsdam University of Potsdam 100 ISSN 1618 - 3193 Archaea, methanogenic bacteria, extreme enviornments Ber. Polarforsch. Meeresforsch. 562 http://epic.awi.de/Publications/Mor2007l.pdf