文献类型：期刊文献

英文题名：Direct conversion of xylan to ethanol by recombinant Saccharomyces cerevisiae strains displaying an engineered minihemicellulosome

作者：Sun, Jie[1,2]; Wen, Fei[1]; Si, Tong[1]; Xu, Jian-He[2]; Zhao, Huimin[1,3]

机构：[1] Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States; [2] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China; [3] Departments of Chemistry, Biochemistry, and Bioengineering, Institute for Genomic Biology, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States

年份：2012

卷号：78

期号：11

起止页码：3837

外文期刊名：Applied and Environmental Microbiology

收录：EI(收录号：20123015281125)

语种：英文

外文关键词：Hydrolysis - Enzymes - Principal component analysis - Yeast - Cell membranes

摘要：Arabinoxylan is a heteropolymeric chain of a β-1,4-linked xylose backbone substituted with arabinose residues, representing a principal component of plant cell walls. Here we developed recombinant Saccharomyces cerevisiae strains as whole-cell biocatalysts capable of combining hemicellulase production, xylan hydrolysis, and hydrolysate fermentation into a single step. These strains displayed a series of uni-, bi-, and trifunctional minihemicellulosomes that consisted of a miniscaffoldin (CipA3/CipA1) and up to three chimeric enzymes. The miniscaffoldin derived from Clostridium thermocellum contained one or three cohesin modules and was tethered to the cell surface through the S. cerevisiae a-agglutinin adhesion receptor. Up to three types of hemicellulases, an endoxylanase (XynII), an arabinofuranosidase (AbfB), and a β-xylosidase (XlnD), each bearing a C-terminal dockerin, were assembled onto the miniscaffoldin by high-affinity cohesin-dockerin interactions. Compared to uni- and bifunctional minihemicellulosomes, the resulting quaternary trifunctional complexes exhibited an enhanced rate of hydrolysis of arabinoxylan. Furthermore, with an integrated D-xylose-utilizing pathway, the recombinant yeast displaying the bifunctional minihemicellulosome CipA3-XynII-XlnD could simultaneously hydrolyze and ferment birchwood xylan to ethanol with a yield of 0.31 g per g of sugar consumed. ? 2012, American Society for Microbiology.