Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/2014
Publication Date: 4/28/2014
Citation: Liu, Z., Cotta, M.A. 2014. Lower-cost cellulosic ethanol production from corn stover using ß-glucosidase producing yeast Clavispora NRRL Y-50464 [abstract].
Technical Abstract: For cellulosic ethanol production, decomposition of cellulosic polymers and enzymatic hydrolysis and saccharification are necessary for microbes to efficiently utilize the biomass harbored sugars. The need of additional enzymes and processing steps increase cost of biofuels. To reduce the cost of cellulosic ethanol production is a critical challenge for sustainable and renewable advanced biofuels productions. Previously, we reported a novel yeast Clavispora sp. NRRL Y-50464 that is able to utilize cellobiose as sole carbon source and produce sufficient native ß-glucosidase enzyme activity for cellulosic ethanol production. One of the enzymatic proteins was characterized and designated as BGL1, ß-glucosidase from Clavispora strain Y-50464. In this study, we report a lower-cost cellulosic ethanol production from corn stover using this yeast strain by simultaneous saccharification and fermentation. Using replicated 2-L bioreactors, an ethanol production of 32g/L was obtained from 20% solid load of undelignated cellulose, at 48 h applying cellulase alone but without addition of ß-glucosidase. Ethanol production reached 35g/L at 120h. The post-fermentation residual cellulose was analyzed and an approximate 90% of efficiency of cellulose utilization was realized. Elimination of exogenous ß-glucosidase in cellulose-to-ethanol fermentation reduced cost and improved efficiency of cellulose conversion. Results of this study showed promising potential of this new yeast strain for sustainable cellulosic ethanol production.