Enzymatic saccharification and bioethanol production from Cynara cardunculus pretreated by steam explosion. (June 2015)

• Record Type: Journal Article
• Authors: Fernandes, Maria C.; Ferro, Miguel D.; Paulino, Ana F.C.; Mendes, Joana A.S.; Gravitis, Janis; Evtuguin, Dmitry V.; Xavier, Ana M.R.B.
• Is Part Of: Bioresource technology. Volume 186(2015)
• Page Start: 309
• Page End: 315
• Publication Date: 2015-06
• Subjects: Steam explosion pretreatment -- Cardoon -- Lignin -- Simultaneous saccharification and fermentation (SSF) -- Separate hydrolysis and fermentation (SHF); Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2015.03.037
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Steam explosion of cardoon (CSE) enhances enzymatic accessibility of cellulose. CSE promotes disruption of interfibrillar surfaces and partial degradation of lignin. Alkali extraction of CSE (CSEOH) increases lignin removal and saccharification. CSEOH simultaneous saccharification and fermentation (SSF) produced 20 g L −1 ethanol. Bioethanol by SSF was more efficient than separate hydrolyses and fermentation (SHF). Abstract: The correct choice of the specific lignocellulosic biomass pretreatment allows obtaining high biomass conversions for biorefinery implementations and cellulosic bioethanol production from renewable resources. Cynara cardunculus (cardoon) pretreated by steam explosion (SE) was involved in second-generation bioethanol production using separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) processes. Steam explosion pretreatment led to partial solubilisation of hemicelluloses and increased the accessibility of residual polysaccharides towards enzymatic hydrolysis revealing 64% of sugars yield against 11% from untreated plant material. Alkaline extraction after SE pretreatment of cardoon (CSEOH) promoted partial removal of degraded lignin, tannins, extractives and hemicelluloses thus allowing to double glucose concentration upon saccharification step. Bioethanol fermentation in SSF mode was faster than SHF process providing the best results: ethanol concentration 18.7 g L −1, fermentation efficiency of 66.6% and a yield of 26.6 g ethanol/100 g CSEOH or 10.1 g ethanol/100 g untreated cardoon.