The Search for More Sustainable Biofuels

Yesterday we wrote about the energy that termites harvest from plants using a combination of the fungus they farm(!) and the microbes in their bellies. To inspire the creation of biofuels, scientists have looked at the gut bacteria in these termites as well as cows to better understand how these animals break down plant materials. The enzymes in the bacteria are able, in varying degrees of success, to convert the cellulose in plants to sugar. The same sugars can be fed to yeast to generate ethanol and other liquid fuels.

This week, researchers from the University of Illinois, publishing in the Proceedings of the National Academy of Sciences, determined that humans can contribute their gut bacteria to biofuel production as well. In fact, the human microbes Bacteroides intestinalis and Bacteroides ovatus appear to be endowed with enzymes that break down a complex plant fiber component more efficiently than the most efficient microbes found in the cow rumen, the researchers report.

“In addition to finding microbes in the cow rumen and termite gut, it looks like we can actually make some contributions ourselves,” says author Isaac Cann. “And our bugs seem to have some enzymes that are even better than those in the cow rumen.” Who knew?

The central controversies around biofuels rest with the plants used. Are they plants that are also used as food for human populations, causing shortages or raising prices? Is the farming of the plants harmful to the environment? Does it require fertilizers or excessive water? Amy Landis, of Arizona State University, is looking at the big picture of biofuels to come up with more sustainable solutions. “We are documenting that there would be environmental benefits, but also trade-offs in growing biofuels that would have to be dealt with,” she explains.

Her potential solution? Lands damaged by industrial waste or other pollutants, including abandoned mining land, could be restored sufficiently to support bioenergy crops. Experimenting in the field, she was able to neutralize the soil and successfully grow crops. This could bring even larger benefits to the lands themselves, including soil remediation and storm water management, according to NSF Discoveries.

Lauren Quinn of the University of Illinois wants to ensure that invasive species aren’t grown as biofuel crops. She and her colleagues put together a “white list” of 49 plants that have low risk of invasion. Read more at Scientific American.

Here’s an interesting idea from scientists at UC Berkeley and Lawrence Berkeley National Laboratory: tobacco to fuel. According to KQED Quest, by adding algae and cyanobacteria to tobacco, the researchers can create a very efficient and cost-effective biofuel. “‘All the things that make tobacco bad are really good for fuels,’ said Bill Shelander [of LBNL],” according to the post. But even though it won’t compete with food crops, there are still issues with this potential biofuel, including heavy pesticide use. Read more at Quest.

And speaking of algae, perhaps abandoning traditional plant materials and going to algae is the best solution. Read more here and here. Finally, why grow the material at all? Why not use organic waste for biofuel, as British Airways plans to use for jet fuel by the end of 2015? Nature News reports on plans to build compact fuel plants all over the world that can convert this waste and create fuel close to where it’s needed (think airports and neighborhoods), cutting down on transportation costs, and well, fuel.

So don’t give up on sustainable biofuels just yet—these greener and more efficient solutions could just be what moves and powers you in the near future!

Image: Switchgrass, USDA/Flickr