title: Glucose-free fructose production from Jerusalem artichoke using a recombinant inulinase-secreting Saccharomyces cerevisiae strain.
abstract: Using inulin (polyfructose) obtained from Jerusalen artichokes, we have produced fructose free of residual glucose using a recombinant inulinase-secreting strain of Saccharomyces cerevisiae in a one-step fermentation of Jerusalem artichoke tubers. For producing fructose from inulin, a recombinant inulinase-producing Saccharomyce cerevisiae strain was constructed with a deficiency in fructose uptake by disruption of two hexokinase genes hxk1 and hxk2. The inulinase gene introduced into S. cerevisiae was cloned from Kluyveromyces cicerisporus. Extracellular inulinase activity of the recombinant hxk-mutated S. cerevisiae strain reached 31 U ml(-1) after 96 h growth. When grown in a medium containing Jerusalem artichoke tubers as the sole component without any additives, the recombinant yeast accumulated fructose up to 9.2% (w/v) in the fermentation broth with only 0.1% (w/v) glucose left after 24 h.
authors.affiliation: State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Jiaxi
authors.initials: J
authors.lastname: Jiang
authors.forename: Wangming
authors.initials: W
authors.lastname: Ji
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Li
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
mesh_terms: D003001:Cloning, Molecular; D005632:Fructose / Q000378:metabolism*; D055786:Gene Knockout Techniques; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D006368:Helianthus / Q000737:chemistry*; D006593:Hexokinase / Q000235:genetics; D007444:Inulin / Q000302:isolation & purification / Q000378:metabolism*; D007716:Kluyveromyces / Q000201:enzymology / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D005632:Fructose; D007444:Inulin; D006593:Hexokinase; D006026:Glycoside Hydrolases; C023086:inulinase