A tiny DNA structure discovered in mud could help us fight climate change
A never-before-identified DNA structure has been discovered that encourages soil bugs to eat methane, a potent greenhouse gas. These structures which have been named Borgs, after the aliens from the TV show Star Trek could be playing an unrecognised role in controlling greenhouse gas emissions, the discovery team concluded in a yet-to-be-published study . Borgs are thought to live inside a bacterial host, because they appear to be unable to fend for themselves. They are comparatively large about one-third the size of the host's own DNA, which is stored in a single chromosome. The research paper has not been published in a scientific journal yet, which means the conclusions havent undergone the rigorous scrutiny of the peer-review process. But this review can take a year or more, said research co-author Jill Banfield, of the University of California, Berkeley. We always post papers before the next step... because it gives other scientists the chance to comment, and potentially catch any errors, she said. READ MORE: * Methane vaccine for cows could be 'game changer' for global emissions * Our hydro dams are bubbling up climate-warming methane * Climate Explained: Methane is short-lived in the atmosphere but leaves long-term damage Before they made the results public, the team sequenced the genetic code of four different versions of this newly-discovered structure. Banfield said the scientists took samples of muds and sequenced all the DNA to see what they could find. If you dig down in mud even a tiny distance, there is no oxygen, and this makes a really nice habitat for certain types of [microbes], including those that make methane. The research team had to fit the sequenced DNA together like a puzzle, said Banfield. In doing so, they found distinct, and relatively long, sequences. Notably, the Borgs have unique genes which rules out the possibility they are a bit of broken DNA. One very notable feature is the number of genes never seen before these stand out like flags, she said. In addition to its own chromosome, a bacterial microbe often has short sections of DNA, known as plasmids, floating around its cell. But these are a lot shorter than the newly discovered Borgs. The team suspects Borgs have picked up their unique genes from an array of different organisms. This assimilation is why theyve been named after the Star Trek aliens. The Borgs earn their keep by boosting the host cells ability to make energy, Banfield said. The discovery could help scientists to better understand how methane is created in waterways and rice paddies. Ultimately, the knowledge could be used to ensure agricultural fields favour cells with Borgs, to minimise methane production, Banfield added. The same may ultimately be possible for other ecosystems. Kiwi scientist Sara Mikaloff-Fletcher a greenhouse gas researcher at Niwa, who isnt connected to the study said the finding could help explain curious findings on global methane. We know from the atmospheric measurements of methane both in here in Aotearoa New Zealand and around the world that methane concentrations started to rise quickly in 2007, after a relatively stable period between 2000 and 2007. Some scientists have suggested that this rapid rise in methane is due to greater wetland production in a warming world, although this remains a topic of debate. Mikaloff-Fletcher said scientists dont have a complete picture of how methane is produced in natural wetlands. A better understanding of the processes controlling earths wetland emissions can give us a clearer picture of what the future might hold and how much we need to reduce methane emissions caused by human activities to meet our climate goals. New Zealands biggest source of methane emissions is livestock, rather than lakes and wetlands. Banfield planned to share the research with colleagues working on this issue to see if the finding could be put to use.