‘Coal-eating’ bugs may solve energy crisis

The Sunday Times

June 28, 2009

Jonathan Leake

Craig Venter, the controversial American scientist who helped decode the human genome, has announced the discovery of ancient bacteria that can turn coal into methane, suggesting they may help to solve the world’s energy crisis.
The bugs, discovered a mile underground by one of Venter’s microbial prospecting teams, are said to have unique enzymes that can break down coal. Venter said he was already working with BP on how to exploit the find.
Venter even suggested the discovery could open up the world’s coalfields to an entirely new form of mining, where coal is infected with the bacteria, allowing methane to be harvested “without even digging up the coal”.
Venter, speaking at the recent La Jolla research and innovation summit, in La Jolla, California, told an audience of researchers and technology investors how he had harvested 20m new genes by analysing the DNA of micro-organisms collected underwater or deep underground.
He said: “We have found a huge number of microbes a mile or so deep in the earth. In fact, there is more diversity under the surface of the earth than in the ocean. It is absolutely stunning.
“Some of these underground water sources have been isolated for 50m to 135m years and we have found totally unique organisms.”
Venter flashed up a black-and-white image of a piece of coal that appeared to be carpeted with a mossy substance.
He said: “We have a large number that eat coal and break it down into organic acids, hydrogen, CO2 and so on. Then we have other organisms with enzymes that can take those organic acids, hydrogen and CO2 and make methane.”
Venter added: “We have a deal with BP to look at the biological conversion of coal into natural gas, where microbes colonise coal particles and produce methane.”
He also showed a second image with coal submerged in a liquid from which bubbles, said to be methane, were rising.
He added: “We and BP think we can scale this up substantially to provide a huge increase in the amount of natural gas available without even digging up the coal.”
Such ideas need to be treated with caution. The biotech industry is renowned for making claims that later turn out to have been excessive. This is often driven by the need to attract investors.
Venter does have a good track record, as shown by his lead role in the race to decode the human genome, but his discovery would need far more research and investment before it could be deployed on an industrial scale.
If it worked, however, the potential would be huge. Coal is the world’s most important fossil fuel with about 6.5 billion tons used each year. This is expected to rise by more than 60% by 2030.
This has serious environmental implications because coal is highly polluting, generating more CO2 per ton than any other major fossil fuel.
There is, however, no ready alternative to coal, especially in power generation, which means greenhouse gas emissions are likely to keep rising for decades if more is burned.
Methane, by contrast, is significantly less polluting. Venter also described separate research that, he said, could one day lead to CO2 being seen as a resource in the manufacture of biofuels.
He described how researchers at Synthetic Genomics, the firm he founded, had genetically engineered an algal species to produce large amounts of lipids — liquid fats that can be used to make biofuels.
All the cells needed was sunlight, a growing medium and CO2. They would then pump out lipids that would float to the top of the container, where they could be skimmed off.
He said: “We see CO2 as raw material. We have been engineering cells to use CO2 driven by sunlight to make biopolymers, methane and sugars.
“One of the most exciting breakthroughs is that we have engineered algal cells to pump out lipids in a pure form into the growing medium. You can literally skim the cream off the top and isolate it like a biocrude and we are not too far away from scaling this up on a very substantial scale.
Venter said: “Why do this? If we look around the world, we are going from 6.5 to 9 billion people in the next 40 years. We have never had the challenge of trying to feed and provide medicine, clean water, shelter and energy for that change in population. We are not doing such a great job right now.”
Click here to watch Venter describe his research