Bioethanol production from steam explosion pretreated and alkali extracted Cistus ladanifer (rockrose)

authors	Ferro, MD; Fernandes, MC; Paulino, AFC; Prozil, SO; Gravitis, J; Evtuguin, DV; Xavier, AMRB
nationality	International
journal	BIOCHEMICAL ENGINEERING JOURNAL
author keywords	Cellulose; Lignin; Cellulase; Simultaneous saccharification and fermentation (SSF); Separate hydrolysis and fermentation (SHF); Ethanol
keywords	ETHANOL-PRODUCTION; ENZYMATIC-HYDROLYSIS; WHEAT-STRAW; ACID PRETREATMENT; CORN STOVER; LIGNOCELLULOSIC BIOMASS; OLIVE STONES; OPTIMIZATION; FRACTIONATION; CELLULOSE
abstract	Biofuels are suitable alternatives to conventional and fossil fuels that pose serious environmental adverse effects to society. Bioethanol is the most promising biofuel and can be generated from lignocellulosic biomasses. Forest residues are outside the human food chain and inexpensive raw materials, but they need a previous pretreatment, in order to improve the cellulose accessibility for further bioconversion. The study of bioethanol production from rockrose pretreated by steam explosion (SE) was carried out employing separate enzymatic hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) approaches. Saccharification of untreated rockrose attained only 0.9% of sugars yield. However, the steam explosion pretreatment promoted the disruption of interfibrillar surfaces of fibers with partial degradation of lignin thus enhancing the accessibility of polysaccharides toward enzymatic hydrolysis. Alkaline extraction after steam explosion pretreatment of rockrose residue (R-SE-OH) led to the partial removal of lignin, hemicelluloses, and other degradation products from fibre surface allowing an increase of 75% in the glucose yield. Bioethanol production in SSF mode was faster and slightly more efficient process than SHE providing the best results: ethanol concentration of 16.1 g L-1, fermentation efficiency of 69.8% and a yield of 22.1 g ethanol/100 g R-SE-OH. (C) 2015 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	1369-703X
year published	2015
volume	104
beginning page	98
ending page	105
digital object identifier (doi)	10.1016/j.bej.2015.04.009
web of science category	Biotechnology & Applied Microbiology; Engineering, Chemical
subject category	Biotechnology & Applied Microbiology; Engineering
unique article identifier	WOS:000362923000014