title: Non-water miscible ionic liquid improves biocatalytic production of geranyl glucoside with Escherichia coli overexpressing a glucosyltransferase.
abstract: Whole cells of Escherichia coli overexpressing a glucosyltransferase from Vitis vinifera were used for the glucosylation of geraniol to geranyl glucoside. A high cell density cultivation process for the production of whole-cell biocatalysts was developed, gaining a dry cell mass concentration of up to 67.6 ± 1.2 g L(-1) and a glucosyltransferase concentration of up to 2.7 ± 0.1 g protein L(-1) within a process time of 48 h. Whole-cell batch biotransformations in milliliter-scale stirred-tank bioreactors showed highest conversion of geraniol at pH 7.0 although the pH optimum of the purified glucosyltransferase was at pH 8.5. The biocatalytic batch process performance was improved significantly by the addition of a water-immiscible ionic liquid (N-hexylpyridinium bis(trifluoromethylsulfonyl)imid) for in situ substrate supply. The so far highest final geranyl glucoside concentration (291 ± 9 mg L(-1)) and conversion (71 ± 2 %) reported for whole-cell biotransformations of geraniol were achieved with 5 % (v/v) of the ionic liquid.
authors.affiliation: Institute of Biochemical Engineering, Technische Universität München, Boltzmannstr. 15, 85748, Garching, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmideder
authors.affiliation: Institute of Biochemical Engineering, Technische Universität München, Boltzmannstr. 15, 85748, Garching, Germany.
authors.forename: Xenia
authors.initials: X
authors.lastname: Priebe
authors.affiliation: Institute of Biochemical Engineering, Technische Universität München, Boltzmannstr. 15, 85748, Garching, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Rubenbauer
authors.affiliation: Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoffmann
authors.affiliation: Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Fong-Chin
authors.initials: FC
authors.lastname: Huang
authors.affiliation: Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354, Freising, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Schwab
authors.affiliation: Institute of Biochemical Engineering, Technische Universität München, Boltzmannstr. 15, 85748, Garching, Germany. d.weuster-botz@lrz.tum.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Weuster-Botz
mesh_terms: D055162:Biocatalysis; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics*; D051228:Geranyltranstransferase / Q000235:genetics*; D005960:Glucosides / Q000096:biosynthesis*; D052578:Ionic Liquids / Q000737:chemistry*; D012995:Solubility; D013729:Terpenes
chemical_list: D003470:Culture Media; D005960:Glucosides; D052578:Ionic Liquids; D013729:Terpenes; C450819:geranyl glucoside; D051228:Geranyltranstransferase
keywords: Escherichia coli; Geranyl glucoside; Glycosyltransferase; Ionic liquid; Whole-cell biotransformation