title: Novel isolates for biological detoxification of lignocellulosic hydrolysate.
abstract: In this paper, two new strians, Issatchenkia occidentalis (Lj-3, CCTCC M 2006097) and Issatchenkia orienalis (S-7, CCTCC M 2006098), isolated from different environments on solid media, were used in the detoxification process of the hemicellulosic hydrolysate of sugarcane bagasse. High-pressure liquid chromatography elution curve of UV-absorption compounds represented by acetic acid, furfural, and guaiacol (toxic compounds found in the hemicellulosic hydrolysate) showed that several chromatographic peaks were evidently diminished for the case of detoxified hydrolysate with isolate strains compared to the high peaks resulted for no detoxified hydrolysate. It was clear that these inhibitors were degraded by the two new isolates during their cultivation process. Fermentation results for the biodetoxified hydrolysate showed an increase in xylitol productivity (Q (p)) by 1.97 and 1.95 times (2.03 and 2.01 g l(-1) h(-1)) and in xylitol yield (Y (p)) by 1.72 and 1.65 times (0.93 and 0.89 g xylitol per gram xylose) for hydrolysate treated with S-7 and Lj-3, respectively, in comparison with no detoxified hydrolysate (1.03 g l(-1) h(-1) and 0.54 g xylitol per gram xylose). This present work demonstrated the importance of Issatchenkia yeast in providing an effective biological detoxification approach to remove inhibitors and improve hydrolysate fermentability, leading to a high xylitol productivity and yield.
authors.affiliation: Phytochemical Department, Guangxi Institute of Botany, The Chinese Academy of Sciences, Yanshan, Guilin City, Guangxi Zhuang Autonomous Region, People's Republic of China. zh-hr@hotmail.com
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hou-Rui
authors.forename: Qin
authors.initials: Q
authors.lastname: Xiang-Xiang
authors.forename: Silvio S
authors.initials: SS
authors.lastname: Silva
authors.forename: Boutros F
authors.initials: BF
authors.lastname: Sarrouh
authors.forename: Cai
authors.initials: C
authors.lastname: Ai-Hua
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yu-Heng
authors.forename: Jin
authors.initials: J
authors.lastname: Ke
authors.forename: Xiang
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000042:Absorption; D001483:Base Sequence; D001673:Biodegradation, Environmental; D005285:Fermentation; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D004718:Saccharomycetales / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D031786:Saccharum / Q000378:metabolism; D014466:Ultraviolet Rays; D014993:Xylitol / Q000096:biosynthesis
chemical_list: C036909:lignocellulose; D008031:Lignin; D014993:Xylitol