Skip to main content
ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #210423
Title: Assessment of Bermudagrass and Bunch Grasses as Feedstock for Conversion to Ethanol

Author
item Anderson, William - Bill
item Dien, Bruce
item BRANDON, S - UNIV OF GA
item PETERSON, JOY - UNIV OF GA

Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2007
Publication Date: 3/30/2008
Citation: Anderson, W.F., Dien, B.S., Brandon, S.K., Peterson, J. 2008. Assessment of bermudagrass and bunch grasses as feedstock for conversion to ethanol. Applied Biochemistry and Biotechnology. 145(1-3):13-21.

Interpretive Summary: It is important to identify appropriate feedstock material for the cellulose to ethanol industry. Besides high yields, feedstocks need to be amenable to efficient conversion via chemical and enzymatic means for fermentation from sugars. Three grass species [giant reed (Arundo donax L.), napiergrass (Pennisetum purpureum Schumach.) and bermudagrass (Cynodon spp)] have shown superior dry matter yields to switchgrass. Little is known on the comparative conversion efficiency of these feedstocks to ethanol via saccharification and fermentation. The objective of this study was to compare leaf and stem material from the three grasses for ethanol production via SSF and better elucidate the differences between bermudagrass genotypes and napiergrass when fermented with pre-treatment enzymes. Conversion via dilute acid pretreatments, sacchification and fermentation was greatest with bermudagrass (140 and 122 mg/g) followed by leaves of napiergrass (107 and 97 mg/g) and giant reed (109 and 85). Variability existed among bermudagrass cultivars for conversion to ethanol following esterase and cellulose treatments with Tifton 85 and Coastcross II being superior to Coastal and Tifton 44. These results suggest that forage quality correlates with conversion efficiency.

Technical Abstract: Research is needed to efficiently use lignocellulose from large plant biomass resources for production of fuel alcohol at lower costs. Ethanol from lignocellulose is limited by the binding of aromatic components to cellulose and hemicelluloses, which forms recalcitrant components in plant biomass. Potential dedicated feedstock species vary in degrees of recalcitrance. A number of grass species have been mentioned as potential feedstocks for the Southeast. Among them are giant reed (Arundo donax L.), napiergrass (Pennisetum purpureum Schumach.) and bermudagrass (Cynodon spp) which have shown superior dry matter yields to switchgrass. Little is known on the comparative conversion efficiency of these feedstocks to ethanol via saccharification and fermentation. The objective of this study was to compare leaf and stem material from the three grasses for ethanol production via SSF and better elucidate the differences between bermudagrass genotypes and napiergrass when fermented with pre-treatment enzymes. Conversion via SSF was greatest with bermudagrass (140 and 122 mg/g) followed by leaves of napiergrass (107 and 97 mg/g) and giant reed (109 and 85). Variability existed among bermudagrass cultivars for conversion to ethanol following esterase and cellulose treatments with Tifton 85 and Coastcross II being superior to Coastal and Tifton 44. These results suggest that forage quality correlates with conversion efficiency.