Complex Sugar Diet Makes Microbe a Good Candidate for Producing Biofuels

Sulfolobus acidocaldarius utilizes glucose and xylose as sole carbon sources.

The Science

Many current biofuel production scenarios involve breaking down biomass into its component sugars and using microbes to convert these sugars into liquid biofuels. However, plant biomass contains long chains of both six- and five-carbon sugars (cellulose and hemicelluloses, respectively) and the commonly used biofuel-producing microbes such as the yeast Saccharomyces cerevisiae or the bacterium Escherichia coli cannot use both sugars simultaneously. Thus, substantial effort and expense is required to separate the sugars prior to conversion to fuels, resulting in reduced overall process efficiency. Now, researchers at the DOE Joint Bioenergy Institute (JBEI) have demonstrated that the microbe Sulfolobus acidocaldarius can simultaneously consume both types of sugars, efficiently consuming even complex substrate mixtures. S. acidocaldarius is an extremophile capable of growing at high temperatures in acidic conditions with an unusually high degree of genome stability. Altogether, these traits make this organism an attractive candidate for metabolic engineering and further development as industrial biofuel producer.

Principal Investigator

Jay D. Keasling
Lawrence Berkeley National Laboratory
[email protected]

BER Program Manager

Dawn Adin

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


Joshua, C. J., R. Dahl, P. I. Benke, and J. D. Keasling. 2011. “Absence of Diauxie During Simultanteous Utilization of Glucose and Xylose by Sulfolobus acidocaldarius,” Journal of Bacteriology 193, 1293–1301. DOI:10.1128/JB.01219-10.