Though it is not the most abundant greenhouse gas, methane is certainly the most potent when it comes to trapping heat within the atmosphere. So while it be far lower in atmospheric concentration than CO2, there is considerable interest in eating away at its presence. Scientists in Europe have made an exciting breakthrough in this area, isolating a previously unknown bacterium that appears to have a ravenous appetite for the gas.
Methane's super radiation-trapping abilities make it around 25 to 30 times more potent than CO2 as a greenhouse gas, and its spread of known sources continue to expand. We know it can come from biomass burning, leaking gas facilities and recently learned that the world's reservoirs are emitting 25 percent more methane than previously realized.
Belching cows are a well known source of methane, and we've seen a number of interesting research projects aimed at curbing their emissions. This includes tweaking their diets to incorporate seaweed or tropical leaves that disrupt the gut eznymes that produce methane, with some promising early results.
But what to do about the methane that is already in the atmosphere? Scientists have known for some time that microbes exist in soil that are consumers of methane, acting as natural methane sinks and playing an important role in balancing out the greenhouse gas effect.
But methane exists in far lower concentrations in the atmosphere than it does in soil, so could there be microbes hungry enough to subsist on only the trace amounts found in the air? While scientists had suspected that there were, it is only now that they've been able to identify them, describing a bacterium called Methylocapsa gorgona, that appears to only need air to thrive, and may take out a number of pollutants while it's at it.
"The bacterium, Methylocapsa gorgona, has surprised us all very much, it is extremely versatile and can not only gain energy and carbon for biomass production from the methane in the air, as we have shown with the help of the NanoSIMS of the University of Vienna, but also fix nitrogen in the air, "explains Michael Wagner from the University of Vienna and author on the study.
Carbon monoxide and hydrogen were other gases to feature as part of the bacterium's metabolism. And not only did the scientists identify the microbe, they were able to come up with a technique to cultivate it in the lab, which they say could be applied to develop similar organisms.
While there is a huge leap between identifying and replicating this microbe and tackling the incredibly complex problem of climate change, scientists now have a new avenue to pursue in their efforts to stem the tide. And in the near term, they write, better understanding of the microbes making up the methane sinks will allow us to better preserve their natural gas-trapping abilities.
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: University of Vienna
