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]

机构：[1]Univ Illinois, Dept Chem & Biomol Engn, Urbana, IL USA;[2]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China; Univ Illinois, Ctr Biophys & Computat Biol, Inst Genom Biol, Dept Chem Biochem & Bioengn, Urbana, IL USA

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：;WOS:【SCI-EXPANDED(收录号:WOS:000304185400007)】；

基金：This work is supported by the Centennial Endowed Chair Fund of the Department of Chemical and Biomolecular Engineering at the University of Illinois at Urbana-Champaign, the East China University of Science and Technology, and the Chinese Scholarship Council (file no. 2008674002).

语种：英文

摘要：Arabinoxylan is a heteropolymeric chain of a beta-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 beta-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.