An international team of researchers has discovered a new group of oil-eating bacteria in the mysterious ecosystem of the Marianas Trench, according to a study published in the newspaper microbiome.
Located in the western Pacific, the deepest part of the trench is 3600 feet below sea level. If you place Mount Everest at the bottom, the summit would still be about 7000 feet from the surface. .
Due to the difficulty of access, there have been only a few expeditions to date to investigate organisms living in this hostile environment, where pressure in some areas can reach the equivalent of 2,400 pounds depressed on a single nail. In fact, scientists say that we know more about Mars than this strange ecosystem of deep waters.
"The Mariana Pit is one of the least studied environments on Earth and there is little information on how microorganisms survive in this unique environment," said David Lea-Smith, author of the study's University of East Anglia in England. Newsweek. "Our initial goal was to determine the biochemical processes used by microorganisms to survive in this environment. For example, what food source do they use and how could they survive extreme pressure conditions? "
In an attempt to address this lack of knowledge, the research team collected microbe samples in the deepest part of the trench using submersible technology. These samples were then analyzed, which allowed them to identify a new group of hydrocarbon degrading bacteria, organic compounds formed from hydrogen and carbon atoms present in many places, including the crude oil and natural gas.
One of the main conclusions of the study was that hydrocarbon degrading bacteria constituted a high proportion of microbes in this environment.
"We were shocked by the fact that hydrocarbon-degrading bacteria were such a large proportion of the total microbial population, much higher than anywhere else on Earth," said Lea-Smith. "This suggests that large quantities of oil are present in the Marianas trench, which these bacteria then use as a source of food."
According to Lea-Smith, we know that similar hydrocarbon degrading organisms – present in almost every environment on the planet – play a major role in the consumption of oil released during events such as the explosion of Deepwater Horizon platform in the Gulf of Mexico.
"These bacteria can play a role in oil consumption reaching the bottom of the ocean, limiting pollution in this environment," he said.
In fact, the authors suggest that a significant proportion of the oil-degrading bacteria that they found in the trench comes from pollution on the surface of the ocean. Surprisingly, they also found natural hydrocarbons in ocean sediments at the bottom of the trench.
"We were also surprised that there are other organisms synthesizing hydrocarbons," said Lea-Smith. "Although I found that the previous work also contained photosynthetic algae and bacteria, the oil on the ocean surface was different from the compounds we found in the Marianas Trench. This suggests that microbes at the bottom of the Mariana Trench use a different type of biochemistry to synthesize these hydrocarbons. "
Researchers believe that these hydrocarbons could help some microbes survive the overwhelming pressures at the bottom of the trench, while providing a source of food for others. However, additional research is needed to shed light on the organisms that live there.
"In future work, we are very interested in determining the biochemical process by which certain microorganisms in the Mariana Trench produce hydrocarbons," said Lea Smith. "These hydrocarbons are similar to the compounds found in diesel fuel. If we can identify this pathway, we could introduce it into other bacteria or yeasts to produce biofuels, which could replace diesel currently produced from fossil fuels. "