An international team of scientists has identified a species of bacteria that can eat away oil spills from ocean water. Researchers from the University of East Anglia, together with colleagues Russia and China, discovered the microbes while exploring the depths of the Mariana Trench in the Western Pacific Ocean. The organisms’ oil-eating properties come from their unique ability to degrade hydrocarbons in their environment. Experts hope that the bacteria can be used to remove pollutants in the Earth’s oceans, especially those produced by human activities. With a depth of approximately 11,000 metres, the Mariana Trench is considered as one of the least explored areas of the world.
Xiao-Hua Zhang, a professor of marine life science at China’s Ocean University and lead author of the UEA study, said researchers know more about Mars than about the deepest part of the Earth. There have only been a few attempts made so far to find out what kinds of organisms can be found in the trench. The UEA researchers set out to explore the deepest areas of the Mariana Trench. They were looking to collect samples of microorganisms living in such depths. What they found were a new group of bacteria that can consume hydrocarbon. Study co-author Jonathan Todd explained that the microbes they discovered can eat away compounds, such as those found in oil, and use them for fuel. Other microorganisms have also been used to break down oil during natural disasters such as the BP oil spill in 2010.
Todd said the Mariana Trench has an abundance of such bacteria. He and his colleagues found that the area does, in fact, have the highest proportion of oil-eating microorganisms in the world. To prove that the microbes are capable of degrading hydrocarbons, the researchers isolated some samples and simulated their natural environment in the trench in a laboratory. Samples of seawater were also collected from the ocean’s surface as well as from the bottom of the Mariana Trench. The UEA scientists found evidence of hydrocarbons some 6,000 metres below the ocean’s surface. However, they believe these compounds are likely from surface pollution that made their way to the bottom. They also detected naturally-occurring hydrocarbons in sediments found at the bottom of the ocean.
This could mean that some microorganisms are capable of producing compounds in such an environment. Researchers have found similar hydrocarbons in algae before but not in microbes, especially those living at such depths. “These hydrocarbons may help microbes survive the crushing pressure at the bottom of the Mariana Trench, which is equal to 1,091 kilograms pressed against a fingernail,” said study co-author Dr David Lea-Smith. “They may also be acting as a food source for other microbes, which may also consume any pollutant hydrocarbons that happen to sink to the ocean floor. But more research is needed to fully understand this unique environment.” The researchers said one of its main goals is to identify microorganisms that can produce hydrocarbons. The findings of the University of East Anglia study are featured in the journal Microbiome.