A variety of wild sorghum that grows on the roadside in northern Australia is showing great potential as a biofuel crop. Researchers from the ARC Centre of Excellence in Plant Cell Walls at the University of Adelaide have discovered that the sorghum variety Arun has the potential to yield over 10,000 liters of bioethanol per hectare per year.

R. Burton, C. Byrt, G Fincher and V. Bulone University of Adelaide

Scientists looked at the stems of 12 varieties of sorghum for sugar content and ease of conversion to ethanol. Varieties included both cultivated and wild relatives. They found that Arun yielded more ethanol than other varieties. The results of the study were published in the journal PLOS ONE.

“Two key advantages of using stem (rather than leaves or grain) to make biofuel is that we can produce this material in low input systems; and as we do not eat this part of the plant we avoid the food versus fuel debate,” explains Caitlin Byrt, postdoctoral fellow in the University’s School of Agriculture, Food and Wine.

The Arun stem contains high levels of a component thought to inhibit bioethanol production. However, research shows that this challenge appears to be offset by a high level of an easily fermentable sugar. The researchers say that a large pool of untapped diversity exists in other species and subspecies of sorghum which opens new avenues of research to generate sorghum lines optimized for biofuel production.

Arcadia Biosciences, a Davis, California-based agricultural technology company, is a partner in the center’s research and is working with the Centre to commercialize these findings. “Commercial application of this work could easily extend to production areas outside Australia,” adds Raj Ketkar, CEO of Arcadia. “We remain keenly interested in collaborating with the Centre and other partners to explore the use of sorghum as an alternative and sustainable energy source.”