Researchers at the Georgia Institute of Technology have unveiled an eco-friendly bacterial protein that can stabilize methane clathrates, ice-like solid compounds made of methane and water.
Methane Hydrate and Climate Change
Enormous amounts of greenhouse gas are trapped under the seafloor. Around the coastlines of the continents, where slopes sink into the sea, small cages of ice trap the methane gas and prevent it from escaping into the atmosphere.
The ice cage formations have gained the scientific community's attention due to their potential effects on climate change. Also known as methane clathrates, the solid compound methane hydrates are considered the energy source of the future but also pose considerable climate risk.
At low temperatures, the methane hydrates on the seafloor are stable. If the water and the seafloor become warmer, these compounds can break down, allowing stored methane to transform into carbon dioxide.
New Insight on Methane Hydrate Stability
The biological process behind the stability of methane gas under the sea has been almost completely unknown. In a recent study, a cross-disciplinary team of researchers discovered an unknown class of bacterial proteins that play a significant role in the formation and stability of methane hydrates.
Led by Professor Jennifer Glass and Professor Raquel Lieberman, the team examined a sample of clay-like sediment obtained from the seafloor off the coast of Oregon. Glass hypothesized that the sediment contains proteins that influence the growth of methane hydrate and that these proteins behave like antifreeze proteins in fish.
To confirm this theory, Glass and her colleagues would need to create the proteins in the laboratory, in spite of the fact that no one had worked with these proteins before and no one knew how they might behave.
After validating the effect of the proteins on the formation and stability of methane hydrate, the researchers used protein crystal structure in carrying out the molecular dynamics simulation. The simulations enabled them to identify the specific site where the protein binds to the methane hydrate.
The study revealed unexpected findings about the structure and function of the proteins. It was found that the proteins do not bind to ice but instead interact with the hydrate structure itself, directing its growth. Additionally, the proteins performed better at modifying methane hydrate than antifreeze proteins tested before.
Preventing methane hydrate formation in natural gas pipelines is a billion-dollar industry. The bacterial proteins can be used in restricting gas leaks, proving to be better than commercial chemicals currently used in drilling. Compared to these compounds, these proteins are non-toxic, eco-friendly, and scalable.
It is also possible that methane hydrates exist throughout the Solar System, such as the subsurface of Mars and on the icy moons like Europa. The findings of this study suggest that if microbes exist on other celestial bodies, they might also produce similar biomolecules that can retain liquid water in regions that can sustain life.
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