title: Characterization of a thermostable xylanase from a newly isolated Kluyvera species and its application for biobutanol production.
abstract: Kluyvera species strain OM3 isolated from spent mushroom substrate could produce a high level of cellulase-free xylanase (5.12 U/mL). This xylanase showed maximum activities at 70 °C and pH 8.0, which could retain 100% and 71% activity after 1h incubation at 60 °C and 70 °C, and maintain stability over a wide range of pHs (5.0-9.0), indicating its thermal and pH stability. Moreover, the xylanase could hydrolyze untreated lignocellulosics (e.g., palm oil fiber) to reducing sugars with a yield of 27.1-46.9 mg/g. A co-culture consisting of Kluyvera sp. strain OM3 and Clostridium sp. strain BOH3 could directly convert birchwood xylan to 1.2g/L butanol, which was comparable to the amount of butanol (1.7 g/L) generated via separate hydrolysis by the xylanase and fermentation by Clostridium sp. strain BOH3. This is the first report on the production, characterization of a xylanase from genus Kluyvera and its application for butanol production directly from hemicelluloses.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore.
authors.forename: Fengxue
authors.initials: F
authors.lastname: Xin
authors.forename: Jianzhong
authors.initials: J
authors.lastname: He
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D000440:Butanols / Q000378:metabolism*; D018920:Coculture Techniques; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D004795:Enzyme Stability; D005285:Fermentation; D006868:Hydrolysis; D044086:Kluyvera / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification*; D008031:Lignin / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D013696:Temperature; D014990:Xylans / Q000378:metabolism
chemical_list: D056804:Biofuels; D000440:Butanols; D014990:Xylans; C036909:lignocellulose; D008031:Lignin; D043364:Endo-1,4-beta Xylanases