A common black fungus, Aspergillus carbonarius ITEM 5010, found in decaying leaves, soil and rotting fruit has been used to to create hydrocarbons, the chief component of petroleum, similar to those in aviation fuels. The fungus produced the most hydrocarbons on a diet of oatmeal but also created them by eating wheat straw or the non-edible leftovers from corn production.

Fungi have been of interest for about a decade within biofuels production as the key producer of enzymes necessary for converting biomass to sugars. Some researchers showed that fungi could create hydrocarbons, but the research was limited to a specific fungus living within a specific tree in the rainforest, and the actual hydrocarbon concentrations were not reported.

Using fungi for hydrocarbon and biofuels production is better than other methods because they do the work themselves, bypassing multiple complicated chemical processes required by other biofuel production methods.The team suspects that fungi produce hydrocarbons, large compounds that are costly for the organism to produce, as a protective mechanism and that fungi react to bacterial attacks by increasing their hydrocarbon production.

Aspergillus carbonarius ITEM 5010. Credit: DOE

Standard Aspergillus fungi have been used to produce enzymes and other useful products, which have been patented and are under commercialization, so a team led by Birgitte Ahring, director and Battelle distinguished professor at Washington State University Tri-Cities, decided to look into A. carbonarius ITEM 5010's potential for biofuels. Kenneth Bruno, a researcher at the U.S. Department of Energy's Pacific Northwest National Laboratory, developed the method essential for the genetic manipulation of A. carbonarius.   

The researchers are now working to optimize the fungi's hydrocarbon production and improve biochemical pathways through genetic engineering. They have obtained mutants with a higher production level and are working on improving these strains by using gene coding for specific hydrocarbons out of blue green bacteria and algae.

It's the same challenge faced by mold researchers nearly a century ago, who found they could only produce a tiny amount of their product. Once they optimized production, we had antibiotics. 

The researchers hope the process leads to economically viable production of aviation biofuels in the next five years.
Published in Fungal Biology.