title: Alcoholic fermentation of Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis in the presence of inhibitory compounds and seawater.
abstract: Production of cellulosic ethanol and holocellulosic ethanol from vegetable or microbial biomass starts with a hydrolysate containing compounds which may produce negative effects in the enzymatic hydrolysis and fermentation stages due to the need of pretreatment of the materials. In this way, the simultaneous presence of hydroxymethylfurfural (HMF), furfural, acetic acid, levulinic acid, and formic acid in different concentrations was tested in the fermentation using Saccharomyces cerevisiae, Pichia stipitis, and Zymomonas mobilis. The substitution of freshwater by seawater in the culture medium was also analyzed. Thus, inhibitory effects were stronger in the fermentation using P. stipitis, followed by Z. mobilis and S. cerevisiae. Formic acid and acetic acid presented more significant effects among the inhibitory compounds, followed by HMF, furfural and levulinic acid. Fermentation performed in culture medium with seawater showed promising results, especially in the ethanol yield using S. cerevisiae (0.50 g ethanol/g glucose) and Z. mobilis (0.49 g ethanol/g glucose). Whereas the production of cellulosic ethanol and holocellulosic ethanol are in early stages of development on an industrial scale, and that the availability and use of freshwater may cause socio-environmental problems for expansion of ethanol production, the use of seawater appears as an alternative to mitigate this problem.
authors.affiliation: Laboratory of Biochemical Engineering, Chemical Engineering Department, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil.
authors.forename: Fabiano Avelino
authors.initials: FA
authors.lastname: Gonçalves
authors.affiliation: Laboratory of Biochemical Engineering, Chemical Engineering Department, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil.
authors.forename: Everaldo Silvino
authors.initials: ES
authors.lastname: dos Santos
authors.affiliation: Laboratory of Biochemical Engineering, Chemical Engineering Department, Federal University of Rio Grande do Norte, Natal, 59078-970, Brazil. gomacedo@eq.ufrn.br.
authors.forename: Gorete Ribeiro
authors.initials: GR
authors.lastname: de Macedo
mesh_terms: D002264:Carboxylic Acids / Q000032:analysis; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D005662:Furaldehyde / Q000032:analysis; D010843:Pichia / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012623:Seawater; D017355:Zymomonas / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D003470:Culture Media; D000431:Ethanol; D005662:Furaldehyde
keywords: Cellulosic ethanol; Fermentation; Holocellulosic ethanol; Inhibitors; Seawater