The Patagonian tree fungus, Gliocladium roseum, expels hydrocarbons which could be used as fuel, scientists say. Image shows the microbe growing as a culture on a petri dish.
Credit: Gary Strobel
PARIS: A reddish microbe discovered at a secret location in the rainforests of northern Patagonia has been found to expel hydrocarbon gas, with promise as a new source of biofuel.
Its potential is so startling that the discoverers have coined the term "myco-diesel" - a derivation of the word for fungus - to describe the various hydrocarbons that it produces as a gas.
A study detailing the find appears next week in the British journal, Microbiology.
Lucky breaks
"This is the only organism that has ever been shown to produce such an important combination of fuel substances," said Gary Strobel, a biologist at Montana State University in Bozeman, USA.
"The fungus can even make these diesel compounds from cellulose, which would make it a better source of biofuel that anything we use at the moment," he said.
Strobel, a 70-year-old veteran of the world's rainforests, said that he came across the fungus, called Gliocladium roseum thanks to "two cases of serendipity."
The first lucky break happened in the late 1990s, when Strobel's team, working in Honduras, came across a previously unidentified fungus called Muscodor albus. By sheer accident, they found that M. Albus releases a powerful, volatile (meaning it readily evaporates into a gas) antibiotic which kills other fungi.
Intrigued by this, the team tested M. Albus on the ulmo tree, whose fibres are a known habitat for fungi, in the hope that this might reveal similar types of fungus. "Quite unexpectedly, G. roseum grew in the presence of these gases when almost all other fungi were killed. It was also making volatile antibiotics," said Strobel.
Alternative biofuels
"Then, when we examined the gas composition of G. roseum, we were totally surprised to learn that it was making a plethora of hydrocarbons and hydrocarbon derivatives. The results were totally unexpected and very exciting, and almost every hair on my arms stood on end," he said.
Strobel's team put the G. roseum through its paces in the lab, growing it on an oatmeal-based jelly and on cellulose. Extractor fans drew off the gases exuded by the fungus, and analysis showed that many of them were hydrocarbons, including at least eight compounds that are the most abundant ingredients in diesel.
Biofuels have been promoted as good alternatives to oil, which is sourced from politically volatile regions and is a major contributor to the greenhouse effect. One of the downsides of biofuels has been their impact on the world food market, because the present generation of fuels is derived from food crops that are grown on farmland.
Another avenue of exploration is in cheap, plentiful non-food fibrous plants and cellulose materials, such as switchgrass, wood chips and straw. But these novel sources, hampered by costs and technical complications, are struggling to reach commercial scale.
"G. roseum can make myco-diesel directly from cellulose, the main compound found in plants and paper," said Strobel. "This means that if the fungus was used to make fuel a step in the production process could be skipped."
"Fungi rush"
Instead of using farmland to grow biofuels, G. roseum could be grown in factories, like baker's yeast, and its gases siphoned off to be liquefied into fuel, he suggested. Another alternative, he said, would be to strip out the enzyme-making genes from the fungus and use this to break down the cellulose to make the biodiesel.
Strobel said Montana State University had filed patents for the fungus, proceeds of which would be shared with local people in Patagonia.
Asked where the fungus had been found, he pointed to the experiences of the 1848 gold rush and said the location had to be protected: "The answer to that is, what if we pushed ourselves back about a hundred and fifty years and you heard a story about a guy finding gold out in California?"
The find is even bigger, said Strobel, than his 1993 discovery of fungus that contained the anticancer drug taxol.
