As the planet is warming and the Earth is undergoing dramatic climate changes, people are starting to pay attention to greenhouse gases and its effect on the climate. However, there are also climate-cooling gases that contribute considerably to climate regulation. One of the most abundant climate-cooling gases is dimethylsulfide (DMS). When released into the atmosphere, DMS generates cloud formation, which reflect sunlight away from Earth. DMS is formed from dimethylsulfoniopropionate (DMSP), an important nutrient in marine environments. Recently, scientists revealed that bacteria were able to produce DMSP.
DMSP was previously thought to be mainly produced by algae on the ocean surface. However, while investigating the sediments along the coast, they found that the amount of DMSP was thousand times larger on the algae-free coastal surfaces than in seawater. They also discovered that the coastal sediment samples were able to synthesize DMSP a few hundred times faster than the seawater samples! The same results were obtained even from samples located in an area that lacked any known DMSP-producing plants and algae. This suggested that there were unknown DMSP producers that might be more efficient than algae and that they have an unprecedentedly large contribution to DMSP production.
They dug deeper into this mystery and analyzed the microbial community on the coastal sediment samples. They looked for a gene called dsyB that is involved in DMSP synthesis, and they found millions of possible DMSP-producing bacteria per gram of sample. Additionally, they managed to identify another abundant gene, mmtN, that is involved in the bacterial DMSP synthesis. Their research was able to show that our previous knowledge of DMSP and DMS was drastically underinformed. After enduring the hottest summer in history, understanding more about the production of DMSP and DMS and how we can manipulate it might prove to be essential to decreasing global temperature.
The question arises: could this be a possible solution to reversing global warming? When algae were previously thought to be the main producers of DMSP, there were actually many proposals to artificially fertilize the ocean to increase DMSP and DMS levels, even as early as in 1987! Even though it was predicted that increasing DMSP producers could decrease the global temperature by 2°C, other models have also shown that artificially increasing DMS levels might drastically reduce rainfall over certain areas in the world, resulting in many new environmental problems. However, with this new knowledge that bacteria can produce DMSP, there is now a significant factor that these previous models have overlooked. We certainly have a lot more to learn about DMSP production and its effect on the environment before we can actually manipulate the climate in an effective way.
Managing Correspondent: Wei Li
Original Article: Bacteria are important dimethylsulfoniopropionate producers in coastal sediments. Nature Microbiology.
Media Coverage: Microorganisms in coast mud can cool the warming climate. Earth.
Image Credit: Wikimedia Commons