Wednesday, November 7, 2007
279-2

Assessment of Bermudagrass as a Feedstock for Ethanol.

William F. Anderson1, Bruce S. Dien2, Sarah K. Brandon3, Joy Doran Peterson3, and Danny E. Akin2. (1) USDA/ARS CBGRU, PO Box 748, Tifton, GA 31793, (2) USDA/ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604, (3) University of Georgia, Dept. of Microbiology, ATHENS, GA 30602

It is critical to determine appropriate dedicated bioenergy feedstock crops for Southern United States. Bermudagrass is considered a good candidate as a feedstock for the conversion of cellulose to ethanol because of its high yields and predominance as a forage and hay crop for the South. There have been significant genetic improvements of rumen digestibility along with increased yields in bermudagrass over the last half century. Preliminary results indicate that the conversion efficiency of bermudagrass to ethanol through simultaneous saccharification and fermentation (SSF) is higher than other grass feedstock including switchgrass. The objective of this study was to evaluate bermudagrass germplasm with variability in rumen digestibility for ethanol production through SSF and enzyme pretreatments. A low stringency conversion protocol was used to compare genotypes for ethanol production and was correlated with rumen digestibility, neutral detergent fiber, and acid detergent fiber data. A select number of germplasm was also assessed for ethanol production using pretreatment enzymes (esterase and cellulase) followed by fermentation. Significant variability exists between bermudagrass accessions and was only moderately correlated with rumen digestibility. Discussion will include methods for breeding and evaluation of bermudagrass as a biofuel feedstock.