title: Simultaneous fermentation of glucose and xylose at elevated temperatures co-produces ethanol and xylitol through overexpression of a xylose-specific transporter in engineered Kluyveromyces marxianus.
abstract: Engineered Kluyveromyces marxianus strains were constructed through over-expression of various transporters for simultaneous co-fermentation of glucose and xylose. The glucose was converted into ethanol, whereas xylose was converted into xylitol which has higher value than ethanol. Over-expressing xylose-specific transporter ScGAL2-N376F mutant enabled yeast to co-ferment glucose and xylose and the co-fermentation ability was obviously improved through increasing ScGAL2-N376F expression. The production of glycerol was blocked and acetate production was reduced by disrupting gene KmGPD1. The obtained K. marxianus YZJ119 utilized 120g/L glucose and 60g/L xylose simultaneously and produced 50.10g/L ethanol and 55.88g/L xylitol at 42°C. The yield of xylitol from consumed xylose was over 98% (0.99g/g). Through simultaneous saccharification and co-fermentation at 42°C, YZJ119 produced a maximal concentration of 44.58g/L ethanol and 32.03g/L xylitol or 29.82g/L ethanol and 31.72g/L xylitol, respectively, from detoxified or non-detoxified diluted acid pretreated corncob.
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Biao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Wang
authors.affiliation: Institutes of Life Sciences, Anhui Medical University, Hefei, Anhui 230032, PR China.
authors.forename: Ruixiang
authors.initials: R
authors.lastname: Han
authors.affiliation: Institutes of Life Sciences, Anhui Medical University, Hefei, Anhui 230032, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ding
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China; Department of Biology and Biochemistry, University of Houston, Houston, TX 77004-5001, USA.
authors.forename: Xiaolian
authors.initials: X
authors.lastname: Gao
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China.
authors.forename: Lianhong
authors.initials: L
authors.lastname: Sun
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China. Electronic address: hjiong@ustc.edu.cn.
authors.forename: Jiong
authors.initials: J
authors.lastname: Hong
mesh_terms: D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005818:Genetic Engineering / Q000379:methods; D005947:Glucose / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+) / Q000235:genetics / Q000378:metabolism; D007218:Industrial Microbiology / Q000379:methods; D007716:Kluyveromyces / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013696:Temperature; D014993:Xylitol / Q000096:biosynthesis* / Q000235:genetics; D014994:Xylose / Q000378:metabolism*; D003313:Zea mays / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; D000431:Ethanol; D014994:Xylose; D050536:Glycerol-3-Phosphate Dehydrogenase (NAD+); D005947:Glucose; D005990:Glycerol; D014993:Xylitol
keywords: Elevated temperature; Ethanol; SSCF; Xylitol; Xylose-specific transporter