sciencetech-blog

comments

Life has been discovered nearly a mile and half underground, raising hopes bacteria might be able to survive deep beneath the surface of other planets.

Researchers found the single-celled organisms living inside coal beds more than 8,000ft (2,440 metres) below the seabed off the coast of Japan. It is the deepest life has yet been found beneath the ocean.

At those depths the spherical microbes have to survive huge pressures that would crush most organisms while having no access to light or oxygen often needed for life.

Scroll down for video 

Researchers found the single-celled organisms living inside coal beds more than 8,000ft (2.4 metres) below the seabed, off the coast of Japan. It is the deepest life has yet been found beneath the ocean. The tiny single celled microbes were found to get nutrients by breaking down coal and other hydrocarbons

Instead, the bacteria scavenge the chemicals they need to survive by breaking down the hydrocarbon compounds in the coal around them.

Scientists from the International Ocean Discovery Program, who made the discovery, said the microbes also have sluggish metabolisms.

The findings, which are to be revealed at the America Geophysical Union Fall Meeting, raise the prospect that life may still be clinging on deep underground on planets such as Mars, where there was once thought to be flowing water on the surface.

Dr Elizabeth Trembath-Reichert, from the California Institute of Technology, who is part of the team that carried out the research, told the Mail Online: 'The deeper we keep looking, the deeper we keep finding life.

'It looks like for the most part they survive on the celery of the microbial world, but when pre-made molecules of another dead cell are available they can take those in and use it as their own rather than having to make everything from scratch themselves, thereby saving energy.'

The microbes were found in core samples taken by the IODP Expedition 337, which took place in 2012 just off the coast of Japan's Shimokital Peninsula in the northwestern Pacific.

A huge drill was lowered more than 3,000 feet (915 metres) through the waves from the research ship Chikyu before then drilling down a further 8,034 feet (2,446 metres) of rock beneath the seafloor.

The microbes were found to be thriving in the cores taken from the coal beds beneath the seafloor, creating what they have called 'coal bed biospheres'.

In an attempt to understand how these bacteria survive, the researchers conducted experiments to feed the microbes a range of different hydrocarbon compounds.

They found that as well as coal, they were also able to eat other small chained fossil fuels found within deep sea oil and gas, breaking them down into methane gas.

However, snacking on these hydrocarbons leaves the microbes with an extremely slow metabolism as they try to use as little energy as possible. 

The research vessel Chikyu drilled nearly a mile and a half (2.4km) below the seabed off Japan's Shimokital Peninsula (pictured). In an attempt to understand how these bacteria survive, the researchers conducted experiments to feed the microbes a range of different hydrocarbon compounds

The researchers found the bacteria thriving in coal samples returned to the surface by the deep sea drilling. They found that as well as coal, the organisms were able to eat other small chained fossil fuels found within deep sea oil and gas, breaking them down into methane gas

Scientists now believe there could be many other microbes living within the coal beds, helping each other to survive in an ecosystem.

Dr Trembath-Reichert said they are also keen to find out how the microbes got there in the first place. Such findings could have implications for where life may be found on other planets.

She said: 'We don't know exactly how they get down there. It is possible they start in a surface environment and the ones we find are just the ones that can survive.

'As we expand our understanding of the habitable zones of life on Earth, we can use these temperatures and pressures to help model where similar conditions may exist on other terrestrial bodies. We may not be limited to the surfaces of other planets.' 

The ship used an enormous deep sea drill to retrieve intact cores of the rock and coal from below the seafloor. Scientists now believe there could be many other microbes living within the coal beds, helping each other to survive in an ecosystem

The expedition spent nearly 70 days at sea while drilling down into the Earth's crust to search for life