A team of Sandia National Laboratory researchers are conducting a fungi-based project that aims to end the “throw it over the fence” approach to biofuels research. “Our idea,” said Craig Taatjes, engine combustion expert at Sandia, “is trying to generate the framework where developing new fuels and understanding their combustion behavior is more tightly linked.” According to Taatjes, under normal circumstances, biochemists are off in their labs generating things that they can produce efficiently, thinking that it will burn, and then they “throw it over the fence” and the combustion people look at what the biochemists have made and try and see how to improve it for combustion. “If we are more tightly coupled,” he said, “the combustion behavior will help to choose the molecules that are made early on” by the biochemists.

A lead biochemist working on the project, Masood Hadi, couldn’t agree more. “Historically what has happened,” he said, “is that combustion people work on their own and the fuels people work on their own and develop some high-value molecule, and then the combustion people say, ‘This doesn’t really work with the conventional engine.’” Hadi said it was decided “that it would be great if we could marry the two disciplines together.”

The result of this approach has led to the fungi-based project that, as Hadi describes, is a nontraditional approach to biofuels research compared to typical work being done today. The research effort is looking at organisms that can be found in nature, which self-digest cellulosic materials and produce molecules that are much closer to what a traditional engine would use. “As we were looking at things,” Hadi said, “we found these fungi that live between plant cell walls.” Now, the team is working with a class of fungi known as endophytes.

The goal of the work, at least for the biochemists, is to study these organisms and look at the pathways in the fungi that are making the molecules that can be used for fuel purposes, eventually moving those molecular systems that make the compounds used in fuel out into a more attractable system, like yeast or bacteria, according to Hadi.

The fungi used in the research were originally found by Gary Strobel of Montana State University, a consultant on the project. Hadi said that Strobel has a theory that the fungi, found in Argentina, could be responsible for some of the Patagonia diesel made in Argentina. But, either way, the fungi produce volatile organic compounds, hydrocarbons that can be used for biofuels. The fungi, which live between plant cell walls and feed off of cellulosic material, produce the hydrocarbons to prevent lethal fungi and bacteria from populating the plant cell, so Hadi said, “This is kind of like the plant’s immune system response and they have evolved over hundreds of years.” The problem, however, is that the fungi will not produce a high amount of the hydrocarbons because if they do, they will kill the host they are living in. Hadi said the fungi produce only in the parts per million, but the goal of the research is to find a way to stop that repression so the fungi will produce “boatloads” of the compounds.

The host organism provides the fungi with cellulosic material and the fungi are like a custom design organism with minimal genomes, and that is all they do, Hadi said. “Our role is to figure out what is the genetic basis for that production of the molecule and identify that through genetic sequencing, molecular chemistry,” and then to figure out what the molecular machines are that are making the compounds.

As for the combustion work on the project, Taatjes said different biofuels will be generated from the platforms that Hadi and his team are investigating, and he wants to be able to understand the combustion behavior of those molecules so that he can help tune which platforms to make. “What I look at is the elementary reactions that happen as the fuel begins to oxidize,” Taatjes said. “These are the reactions that largely determine the fuel dependants of the fuel behavior.” Ultimately, the work by the combustion team will help the biologist determining what compounds they should stop the fungus from making, and what compounds they should have the fungus make more of. Even if they don’t know a lot about the fungus, looking at how certain molecules generated from the fungus perform in combustion tests will help form a predictive model for which molecules to go after, Taatjes explained.

The window for the research project is roughly three years, and along with Hadi and Taatjes, the project will include help from fungi expert Strobel, as well as another engine combustion specialist, John Dec, and even an ignition chemistry modeler from MIT.

There is a lot that could be looked at, Taatjes said, but “we are trying to look at what should be looked at.”