Could a bacteria that feeds on methane be a tool in the climate change toolbox?

Methane is an atmospheric trace gas whose concentration has steadily increased since the beginning of the industrial age and which as a greenhouse gas contributes significantly to the warming of the earth. While many processes are known that contribute to methane production, only specific microorganisms can biologically remove methane from the atmosphere and are therefore important for the greenhouse gas balance of the earth. Now an international research team with the participation of Craig Herbold, Andreas Richter, Arno Schintlmeister and Michael Wagner from the University of Vienna has bred a microorganism in the laboratory that can only live on air. The results are currently published in the renowned journal PNAS.

Methane (CH 4 ) is present in the atmosphere in very small quantities – only about 1.8 parts in one million parts of air are CH 4, Nevertheless, methane is a potent greenhouse gas responsible for about 15 percent of global warming. It is caused by a large number of degradation processes in low-oxygen soils and sediments, as well as in some industrial processes. Since the early 20th century, bacteria have been known to degrade methane in soils or sediments, but methane is found in much higher concentrations than in the atmosphere. It has been known for some time that there must be bacteria that metabolize the extremely low levels of methane in the atmosphere. However, despite intensive efforts so far, no one has managed to breed microbes in the laboratory that only needed air to grow. That’s why people always doubted 

“We have now for the first time been able to isolate a methane-degrading bacterium that can really live on air,” says Alexander Tveit from the University of Tromsø, first author of the study and former PostDoc at the Department of Microbiology and Ecosystem Research at the University of Vienna. For this purpose, a special technique for the cultivation of air-feeding microbes has been developed, which is now also suitable for the cultivation of other similar organisms.

“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, head of the Center for Microbiology and Environmental Systems Science.” Genomic and proteomic analysis also showed that the bacterium contains not only methane, but also the respiration of carbon monoxide and hydrogen, which are also in minute quantities in the atmosphere, can gain energy, “adds Andreas Richter, meaning that Methylocapsa uses gorgona with nitrogen, oxygen, carbon dioxide, methane,Carbon Monoxide and Hydrogen six gases of air directly for its growth, making it a true specialist in the life of air alone.