title: Enhancing ethanol production from cellulosic sugars using Scheffersomyces (Pichia) stipitis.
abstract: Studies were performed on the effect of CaCO3 and CaCl2 supplementation to fermentation medium for ethanol production from xylose, glucose, or their mixtures using Scheffersomyces (Pichia) stipitis. Both of these chemicals were found to improve maximum ethanol concentration and ethanol productivity. Use of xylose alone resulted in the production of 20.68 ± 0.44 g L(-1) ethanol with a productivity of 0.17 ± 0.00 g L(-1) h(-1), while xylose plus 3 g L(-1) CaCO3 resulted in the production of 24.68 ± 0.75 g L(-1) ethanol with a productivity of 0.21 ± 0.01 g L(-1) h(-1). Use of xylose plus glucose in combination with 3 g L(-1) CaCO3 resulted in the production of 47.37 ± 0.55 g L(-1) ethanol (aerobic culture), thus resulting in an ethanol productivity of 0.39 ± 0.00 g L(-1) h(-1). These values are 229 % of that achieved in xylose medium. Supplementation of xylose and glucose medium with 0.40 g L(-1) CaCl2 resulted in the production of 44.84 ± 0.28 g L(-1) ethanol with a productivity of 0.37 ± 0.02 g L(-1) h(-1). Use of glucose plus 3 g L(-1) CaCO3 resulted in the production of 57.39 ± 1.41 g L(-1) ethanol under micro-aerophilic conditions. These results indicate that supplementation of cellulosic sugars in the fermentation medium with CaCO3 and CaCl2 would improve economics of ethanol production from agricultural residues.
authors.affiliation: Department of Animal Sciences and Ohio State Agricultural Research and Development Center, The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH, 44691, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Okonkwo
authors.affiliation: Crop Improvement Section, Plant Breeding Unit, Indian Institute of Rice Research, Rajendra Nagar, Hyderabad, 500 030, TS, India.
authors.forename: M M
authors.initials: MM
authors.lastname: Azam
authors.affiliation: Department of Animal Sciences and Ohio State Agricultural Research and Development Center, The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH, 44691, USA. Ezeji.1@osu.edu.
authors.forename: T C
authors.initials: TC
authors.lastname: Ezeji
authors.affiliation: Bioenergy Research Unit, United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N University Street, Peoria, IL, 61604, USA. Nasib.Qureshi@ars.usda.gov.
authors.forename: N
authors.initials: N
authors.lastname: Qureshi
mesh_terms: D000332:Aerobiosis; D000818:Animals; D002482:Cellulose / Q000378:metabolism*; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006801:Humans; D010843:Pichia / Q000378:metabolism*
chemical_list: D003470:Culture Media; D000431:Ethanol; D002482:Cellulose
keywords: CaCO3; CaCl2; Ethanol; Mixed cellulosic sugars; Productivity; Xylose