How Do Microbes Make Methane?

A chemical compound made up of one-part carbon and four parts hydrogen, methane may be the simplest alkane but when it comes to natural gas, its inherently important. To date, little was known about the biological processes that see a diverse range of microorganisms produce methane. But now, thanks to new research published in the journal Science, researchers have uncovered new insight into how microbes convert organic carbon to methane. For the scientific community, the discovery could spark new ways to boost reaction speed times, as well as reverse the process entirely.  

Finding the value in methanogenic microbes

Forget blaming cows alone. On a global scale, methanogenic microbes account for 90% of the world’s methane emissions. Yet while they do contribute to the creation of the greenhouse gas, their ability to break down plant material into easily burnable gas could make methanogenic microbes an invaluable ingredient when it comes to biofuel production.

With new research to back their claims, biochemists are maintaining that the multi-step process unfolds according to the methyl radical mechanism. This nullifies the alternative methyl-nickel theory, which was also a popular model.

Chemistry, in slow motion

In the past, scientists were unable to determine which model was correct, due to the fact that the processes occurred at such a fast rate. But now, armed with the chemical equivalent of a slow motion camera, Dr. Thanyaporn Wongnate and a team of researchers from the University Michigan were able to capture the reaction process. As well as confirming the dominance of the methyl-free radical path, the study also explored how reaction speeds are affected by temperature and other variable factors.

According to Northwestern University's Dr. Amy Rosenzweig, the pioneering work “ends more than two decades of controversy and sets the stage for building a consensus MCR [methyl-coenzyme M reductase] mechanism.” That said, she adds that “several key questions remain unanswered,” including whether methane oxidation is a precise reversal of the initial process, or whether it takes a variation of the path.  

When it comes to climate change, methane is a hugely volatile component. The same goes for the presence of gases such as dichlorodifluoromethane in drinking and surface water. For more information on how scientists test for VOCs, ‘Trace Level VOC Analysis in Different Sample Matrices’ explores specialised sample techniques, as well as the GC-MS analysis process. Using the next generation VSP4000 (Versatile Sample Preparator) purge and trap system, quality control personnel are able to hone in on ultra-low detection limits, and minimise the risks of contamination.