title: Extracellular secretion of β-glucosidase in ethanologenic E. coli enhances ethanol fermentation of cellobiose.
abstract: Consolidated bioprocessing of lignocellulose for ethanol production is realized by expressing cellulase enzymes on ethanologenic strain. In this study, an ethanologenic Escherichia coli ZY81 was constructed by integrating pyruvate decarboxylase gene pdc and alcohol dehydrogenase gene adhB from Zymomonas mobilis into the genome of E. coli JM109 to obtain the capability of ethanol production. Then, the β-glucosidase gene bglB from Bacillus polymyxa was cloned and secretively expressed in E. coli ZY81. The recombinant strain E. coli ZY81/bglB showed an obvious activity of β-glucosidase in extracellular location with more than half in periplasmic space. EDTA was found to promote the release of the periplasmic proteins by approximately tenfold. E. coli ZY81/bglB utilized cellobiose as sole carbon source for ethanol production with 33.99 % of theoretical yield.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
authors.forename: Zichen
authors.initials: Z
authors.lastname: Luo
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Bao
mesh_terms: D001483:Base Sequence; D002475:Cellobiose / Q000378:metabolism*; D017931:DNA Primers; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D002475:Cellobiose; D000431:Ethanol; D001617:beta-Glucosidase