Methane is the dominant ingredient of natural gas, a result of complex, gooey organic molecules being chopped up into smaller pieces by industrious microbes or the pressure cooker burial of geological activity.
The microbial instigators are members of the archaeal domain, producing methane from just a few precursors: carbon dioxide, methanol, methylamines, and dimethylsulfide.
Mayumi tested ten types of previously isolated methanogens by feeding them several different flavors of MACs and looking for methane production.
To move up the ladder of complexity / realism, the team next fed the two winning strains coal with different MAC abundances.
Again, the microbes made methane, but the activity rates seem to be pretty slow, so it’s unclear exactly how much this new metabolism contributes to natural gas production in coal beds.
The team’s findings are a compelling indication of a previously unknown metabolism, a new way for microbes to make a living through biochemical innovation.
The vast majority of microbes have not been isolated, and the ability to produce methane seems to exist beyond canonical methanogens.
These factors suggest that coal-based metabolism is an intricate process involving several members of a microbial community; making methane from MACs is likely just the tip of the iceberg.
Microbial innovation has picked up the slack: the discovery of “Methoxydotrophic methanogens”, turning coal derivatives into natural gas, shows yet another way they sustain our planet and underlie our way of life.