Preservation of methanogenic, hydrogen-utilizing microbial cultures

A method for preserving methanogens, the method comprising drying a liquid culture comprising the methanogen in air to obtain a dried culture comprising the methanogens, wherein prior to the performing drying, the liquid culture was grown in the presence of oxygen, and wherein after the dried culture is reconstituted, the reconstituted culture retains a relatively high specific methanogenic activity against H2:CO2 after drying as compared to a reconstituted culture that was not grown in the presence of oxygen, and wherein the specific methanogenic activity against H2:CO2 is at least 30% of the specific methanogenic activity of the liquid culture against H2:CO2 prior to drying.