Agave proves to be a low recalcitrant lignocellulosic feedstock for biofuels production on semi-arid lands.
BACKGROUND
Agave, which is well known for tequila and other liquor production in Mexico, has recently gained attention because of its attractive potential to launch sustainable bioenergy feedstock solutions for semi-arid and arid lands. It was previously found that agave cell walls contain low lignin and relatively diverse non-cellulosic polysaccharides, suggesting unique recalcitrant features when compared to conventional C4 and C3 plants.


RESULTS
Here, we report sugar release data from fungal enzymatic hydrolysis of non-pretreated and hydrothermally pretreated biomass that shows agave to be much less recalcitrant to deconstruction than poplar or switchgrass. In fact, non-pretreated agave has a sugar release five to eight times greater than that of poplar wood and switchgrass . Meanwhile, state of the art techniques including glycome profiling, nuclear magnetic resonance (NMR), Simon's Stain, confocal laser scanning microscopy and so forth, were applied to measure interactions of non-cellulosic wall components, cell wall hydrophilicity, and enzyme accessibility to identify key structural features that make agave cell walls less resistant to biological deconstruction when compared to poplar and switchgrass.


CONCLUSIONS
This study systematically evaluated the recalcitrant features of agave plants towards biofuels applications. The results show that not only does agave present great promise for feeding biorefineries on semi-arid and arid lands, but also show the value of studying agave's low recalcitrance for developments in improving cellulosic energy crops.
Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, 900 University Ave, Riverside, CA 92507, USA ; Center for Environmental Research and Technology, University of California, 1084 Columbia Ave, Riverside, CA 92507, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA ; Current address: DuPont Industrial Biosciences, 925 Page Mill Rd, Palo Alto, CA 94304, USA.
Hongjia
H
Li
Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd., Athens, GA 30602, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Sivakumar
S
Pattathil
Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th St. NW, Atlanta, GA 30332, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA ; Current address: Energy, Environmental & Chemical Engineering Department, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA.
Marcus B
MB
Foston
National Renewable National Laboratory, 15013 Denver W Pkwy, Golden, CO 37831, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Shi-You
SY
Ding
Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, 900 University Ave, Riverside, CA 92507, USA ; Center for Environmental Research and Technology, University of California, 1084 Columbia Ave, Riverside, CA 92507, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Rajeev
R
Kumar
Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, 900 University Ave, Riverside, CA 92507, USA ; Center for Environmental Research and Technology, University of California, 1084 Columbia Ave, Riverside, CA 92507, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Xiadi
X
Gao
National Renewable National Laboratory, 15013 Denver W Pkwy, Golden, CO 37831, USA.
Ashutosh
A
Mittal
National Renewable National Laboratory, 15013 Denver W Pkwy, Golden, CO 37831, USA.
John M
JM
Yarbrough
National Renewable National Laboratory, 15013 Denver W Pkwy, Golden, CO 37831, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Michael E
ME
Himmel
Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th St. NW, Atlanta, GA 30332, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Arthur J
AJ
Ragauskas
Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Rd., Athens, GA 30602, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Michael G
MG
Hahn
Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, 900 University Ave, Riverside, CA 92507, USA ; Center for Environmental Research and Technology, University of California, 1084 Columbia Ave, Riverside, CA 92507, USA ; BioEnergy Science Center, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
Charles E
CE
Wyman
Agave; Biofuels; Feedstock; Low recalcitrance; Semi-arid land