An international team of researchers has found bacterial communities within microscopic spheroidal aggregates of dolomite, oil and water found in sheets of frozen methane and ice, known as ‘flammable ice,’ in Joetsu Basin, Japan Sea.
Epifluorescence imagery of a tiny grain within methane hydrate showing internal presence of microbial DNA. Image credit: Snyder et al, doi: 10.1038/s41598-020-58723-y.
“We’re melting hydrate to study methane gas when we noticed an unusual powder consisting of microscopic spheroids with mysterious dark cores,” said Dr. Glen T. Snyder, a researcher at the Meiji University Global Front, Japan.
“We then set about collecting a group of like-minded scientists to investigate further.”
Using innovative analytical techniques, Dr. Snyder and colleagues were able to show that oil was being degraded in the microenvironments within ‘flammable ice.’
“In combination with the other evidence collected by my colleagues, my results showed that even under near-freezing temperatures, at extremely high pressures, with only heavy oil and saltwater for food-sources, life was flourishing and leaving its mark,” said Dr. Stephen Bowden, a researcher at the University of Aberdeen.
The methane in ‘flammable ice’ is known to form as microbes degrade organic matter on the seafloor.
“But what we never expected to find was microbes continuing to grow and produce these spheroids, all of the time while isolated in tiny cold dark pockets of saltwater and oil,” Dr. Snyder continued said.
“It certainly gives a positive spin to cold dark places, and opens up a tantalising clue as to the existence of life on other planets.”
“It certainly changes how I think about things,” Dr. Bowden said.
“Providing they have ice and a little heat, all those frigid cold planets at the edge of every planetary system could host tiny microhabitats with microbes building their own ‘death stars’ and making their own tiny little atmospheres and ecosystems, just as we discovered here.”
The team’s paper was published in the journal Scientific Reports.
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G.T. Snyder et al. 2020. Evidence in the Japan Sea of microdolomite mineralization within gas hydrate microbiomes. Sci Rep 10, 1876; doi: 10.1038/s41598-020-58723-y
