title: Bioprocessing of agricultural residues to ethanol utilizing a cellulolytic extremophile.
abstract: A recently discovered thermophilic isolate, Geobacillus sp. R7, was shown to produce a thermostable cellulase with a high hydrolytic potential when grown on extrusion-pretreated agricultural residues such corn stover and prairie cord grass. At 70°C and 15-20% solids, the thermostable cellulase was able to partially liquefy solid biomass only after 36 h of hydrolysis time. The hydrolytic capabilities of Geobacillus sp. R7 cellulase were comparable to those of a commercial cellulase. Fermentation of the enzymatic hydrolyzates with Saccharomyces cerevisiae ATCC 24860 produced ethanol yields of 0.45-0.50 g ethanol/g glucose with more than 99% glucose utilization. It was further demonstrated that Geobacillus sp. R7 can ferment the lignocellulosic substrates to ethanol in a single step that could facilitate the development of a consolidated bioprocessing as an alternative approach for bioethanol production with outstanding potential for cost reductions.
authors.affiliation: Center for Bioprocessing Research and Development, South Dakota School of Mines and Technology, Rapid City, 57701, USA.
authors.forename: Vasudeo P
authors.initials: VP
authors.lastname: Zambare
authors.forename: Aditya
authors.initials: A
authors.lastname: Bhalla
authors.forename: Kasiviswanath
authors.initials: K
authors.lastname: Muthukumarappan
authors.forename: Rajesh K
authors.initials: RK
authors.lastname: Sani
authors.forename: Lew P
authors.initials: LP
authors.lastname: Christopher
mesh_terms: D056804:Biofuels; D002480:Cellulase / Q000378:metabolism*; D005285:Fermentation; D056506:Geobacillus / Q000201:enzymology* / Q000254:growth & development*; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D006109:Poaceae; D003313:Zea mays
chemical_list: D056804:Biofuels; C036909:lignocellulose; D008031:Lignin; D002480:Cellulase