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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #233223
Title: Hydrolysis of Tifton 85 bermudagrass by a pressurized batch hot water reactor

Author
item BRANDON, S - UNIV OF GA
item EITEMAN, M - UNIV OF GA
item PATEL, K - UNIV OF GA
item RICHBOURG, M - UNIV OF GA
item MILLER, D - UNIV OF GA
item Anderson, William - Bill
item PETERSON, J - UNIV OF GA

Submitted to: American Society for Microbiology Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/8/2007
Publication Date: 11/8/2007
Citation: Brandon, S.K., Eiteman, M.A., Patel, K., Richbourg, M.M., Miller, D.J., Anderson, W.F., Peterson, J.D. 2007. Hydrolysis of Tifton 85 bermudagrass by a pressurized batch hot water reactor. Southeastern Branch Meeting of the American Society for Microbiology. Auburn University, AL.

Interpretive Summary: not required

Technical Abstract: Ethanol production from grass is desirable due to the large amount of biomass it produces. However, a pretreatment is necessary before fermentation to increase ethanol yield. Tifton 85 bermudagrass was treated with a newly designed pressurized batch hot water reactor. Multiple temperatures, pressures, and reaction times were evaluated, and reducing sugars liberated during enzymatic hydrolysis were determined. Pressure had a negligible effect on digestibility of the grass, and a reaction temperature of 230°C for two minutes was the most effective in releasing reducing sugars. Fermentations were conducted with untreated grass and with grass treated for two minutes at 200°C or 230°C to confirm that the increase in reducing sugar concentration resulted in an increased ethanol yield. Following hydrolysis with 2 filter paper units (FPU) of a mixed cellulase enzyme cocktail per gram dry weight of grass, fermentations were performed with engineered Escherichia coli strain LY01. Grass treated at 230°C produced 14.7 g/L of ethanol, which was significantly higher than 200°C treated grass (11.0 g/L) and untreated grass (9.0 g/L). Ferulic and para-coumaric acids were also released during the fermentations. Based on these results, pressurized batch hot water reactor pretreatment is effective in increasing ethanol yield of grass in fermentation.