title: Multistage process for the production of bioethanol from almond shell.
abstract: This work describes the feasibility of using almond shell as feedstock for bioethanol production. A pre-treatment step was carried out using 4% NaOH for 60min at 121°C followed by 1% sulfuric acid for 60min at 121°C. Enzymatic saccharification of the pre-treated almond shell was performed using Penicillium occitanis enzymes. The process was optimized using a hybrid design with four parameters including the incubation time, temperature, enzyme loads, and polyethylene glycol (PEG) concentration. The optimum hydrolysis conditions led to a sugar yield of 13.5%. A detoxification step of the enzymatic hydrolysate was carried out at pH 5 using 1U/ml of laccase enzyme produced by Polyporus ciliatus. Fermenting efficiency of the hydrolysates was greatly improved by laccase treatment, increasing the ethanol yield from 30% to 84%. These results demonstrated the efficiency of using almond shell as a promising source for bioethanol production.
authors.affiliation: Enzymes and Bioconversion Unit, National Engineering School, P.O. Box 1173-3038, Sfax University, Tunisia. Electronic address: imenkacem2009@yahoo.fr.
authors.forename: Imen
authors.initials: I
authors.lastname: Kacem
authors.affiliation: Sorbonne Universités, Université de Technologie de Compiègne, Département Génie des Procédés Industriels, Laboratoire Transformations Intégrées de la Matière Renouvelable (UTC/ESCOM, EA 4297 TIMR), Centre de Recherche de Royallieu, B.P. 20529, 60205 Compiègne Cedex, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Koubaa
authors.affiliation: Institut de l'Olivier, laboratoire d'amélioration de la productivité de l'olivier et la qualité du produit, Route de l'aéroport km 1.5, B.P. 1087, Sfax, Tunisia.
authors.forename: Sameh
authors.initials: S
authors.lastname: Maktouf
authors.affiliation: Enzymes and Bioconversion Unit, National Engineering School, P.O. Box 1173-3038, Sfax University, Tunisia.
authors.forename: Fatma
authors.initials: F
authors.lastname: Chaari
authors.affiliation: Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Campus Universitaire, 2092 El-Manar II, Tunis, Tunisia.
authors.forename: Taha
authors.initials: T
authors.lastname: Najar
authors.affiliation: Laboratory of Industrial Chemistry II, National Engineering School, P.O. Box 1173-3038, Sfax University, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Chaabouni
authors.affiliation: Enzymes and Bioconversion Unit, National Engineering School, P.O. Box 1173-3038, Sfax University, Tunisia.
authors.forename: Nadia
authors.initials: N
authors.lastname: Ettis
authors.affiliation: Enzymes and Bioconversion Unit, National Engineering School, P.O. Box 1173-3038, Sfax University, Tunisia.
authors.forename: Semia
authors.initials: S
authors.lastname: Ellouz Chaabouni
mesh_terms: D019149:Bioreactors; D002241:Carbohydrates / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D042845:Laccase / Q000737:chemistry; D010407:Penicillium / Q000201:enzymology; D000068181:Prunus dulcis / Q000737:chemistry*; D013464:Sulfuric Acids
chemical_list: D002241:Carbohydrates; D013464:Sulfuric Acids; D000431:Ethanol; D042845:Laccase; C033158:sulfuric acid
keywords: Almond shell; Bioethanol; Laccase; Pre-treatment; Saccharification