title: Hemicellulosic ethanol production by immobilized cells of Scheffersomyces stipitis: effect of cell concentration and stirring.
abstract: Bioconversion of hemicellulosic hydrolysate into ethanol plays a pivotal role in the overall success of biorefineries. For the efficient fermentative conversion of hemicellulosic hydrolysates into ethanol, the use of immobilized cells system could provide the enhanced ethanol productivities with significant time savings. Here, we investigated the effect of 2 important factors (e.g., cell concentration and stirring) on ethanol production from sugarcane bagasse hydrolysate using the yeast Scheffersomyces stipitis immobilized in calcium alginate matrix. A 2(2) full factorial design of experiment was performed considering the process variables- immobilized cell concentration (3.0, 6.5 and 10.0 g/L) and stirring (100, 200 and 300 rpm). Statistical analysis showed that stirring has the major influence on ethanol production. Maximum ethanol production (8.90 g/l) with ethanol yield (Yp/s) of 0.33 g/g and ethanol productivity (Qp) of 0.185 g/l/h was obtained under the optimized process conditions (10.0 g/L of cells and 100 rpm).
authors.affiliation: a Department of Biotechnology, Engineering School of Lorena , University of São Paulo ; Lorena , Brazil.
authors.forename: Thais S S
authors.initials: TS
authors.lastname: Milessi
authors.forename: Felipe A F
authors.initials: FA
authors.lastname: Antunes
authors.forename: Anuj K
authors.initials: AK
authors.lastname: Chandel
authors.forename: Silvio S
authors.initials: SS
authors.lastname: da Silva
mesh_terms: D018914:Cells, Immobilized / Q000737:chemistry / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D011134:Polysaccharides / Q000378:metabolism*; D004718:Saccharomycetales / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D000431:Ethanol; C007916:hemicellulose
keywords: 2G, second generation; ANOVA, analysis of variance; CO2, carbon di-oxide; Ca-alginate, calcium alginate; HPLC, high performance liquid chromatography; Min, minutes; Qp, ethanol productivity; SB, sugarcane bagasse; Scheffersomyces stipitis; Yp/s, ethanol yield; bioethanol; cell immobilization; df, degree of freedom; dilute acid hydrolysis; sugarcane bagasse hydrolysate