Tree fungus found to produce diesel
Recently discovered fungus is potentially a new source of green energy and scientists are now working to develop its fuel producing potential.Posted May 5, 2009
Gary Strobel, a plant pathologist at Montana State University, Bozeman, and colleagues report that Gliocladium roseum, a fungus found in rainforest trees, produces dozens of the same hydrocarbons found in gasoline, diesel fuel, and jet fuel. The fungus may help companies convert the chemical energy stored in plants into liquid fuels capable of replacing fossil fuels.
Strobel’s discovery came unexpectedly when he discovered a fungus in the Ulmo tree in the Patagonia rainforest. Strobel and colleagues cultured the organism, collected the gaseous compounds it produced, and ran the compounds through a mass spectrometer to identify them. When he saw the printout, Strobel says, “every hair on my body stood up.” The list included octane, 1-octene, heptane, 2-methyl, and hexadecane—all common components of diesel fuels.
Although other microbes are known to make individual volatile hydrocarbons common in fuels, Strobel says none can match the synthetic repertoire of G. roseum, which makes a staggering 55 volatile hydrocarbons: “No one has ever observed anything like this with any microbe before.”
Strobel and his colleagues also cultured G. roseum by feeding it cellulosic biomass like that from agricultural wastes, although the yield of volatile hydrocarbons declined. Even if the bug turns out not to produce fuels economically, however, renewable-fuel companies are likely to try to adopt its synthetic prowess to boost the biofuel output of their own organisms.
“In fact, the genes of the fungus are just as useful as the fungus itself in the development of new biofuels.”
“We were very excited to discover that G. roseum can digest cellulose. Although the fungus makes less myco-diesel when it feeds on cellulose compared to sugars, new developments in fermentation technology and genetic manipulation could help improve the yield,” said Professor Strobel. “In fact, the genes of the fungus are just as useful as the fungus itself in the development of new biofuels.”
“When crops are used to make biofuel they have to be processed before they can be turned into useful compounds by microbes,” said Strobel. “G. roseum can make myco-diesel directly from cellulose, the main compound found in plants and paper. This means if the fungus was used to make fuel, a step in the production process could be skipped.”
Strobel is currently working with his son, Scott, an enzymologist at Yale University, and other researchers to sequence G. roseum’s complete genome and identify its component enzymes.
“The discovery also questions our knowledge of the way fossil fuels are made. The accepted theory is that crude oil, which is used to make diesel, is formed from the remains of dead plants and animals that have been exposed to heat and pressure for millions of years,” said Professor Strobel. “If fungi like this are producing myco-diesel all over the rainforest, they may have contributed to the formation of fossil fuels.”
Society for General Microbiology
“The production of myco-diesel hydrocarbons and their derivatives by the endophytic fungus Gliocladium roseum (NRRL 50072)” read article
Colorized environmental scanning electron microscope photo of Gliocladium roseum, an endophtic fungus that produces myco-diesel hydrocarbons. (Photo courtesy of Gary Strobel.