Substrates: 79% of the activity with D-glucose and NADP+. The enzyme shows also activity with D-xylose and NAD+ as cofactor, D-glucose (NADP+ or NAD+ as cofactor), D-fucose (cofactor NADP+) and D-galactose (cofactor NADP+) Products: -
Substrates: 79% of the activity with D-glucose and NADP+. The enzyme shows also activity with D-xylose and NAD+ as cofactor, D-glucose (NADP+ or NAD+ as cofactor), D-fucose (cofactor NADP+) and D-galactose (cofactor NADP+) Products: -
engineering of non-conventional yeast Pichia kudriavzevii strain VTT C-79090T to recombinantly express the D-xylose dehydrogenase coding gene from Caulobacter crescentus. With this single modification the recombinant strain VTT C-79090T produces up to 171 g/l of D-xylonate from 171 g/l D-xylose at a rate of 1.4 g/l/h and a high yield, which is comparable with D-xylonate production by Gluconobacter oxydans or Pseudomonas sp. The productivity of the strain is also remarkably high at low pH, producing 146 g/l D-xylonate at pH 3.0. Comparison to production of D-xylonate from Saccharomyces cerevisiae strain VTT B-67002 expressing the gene from Caulobacter crescentus, overview
engineering of non-conventional yeast Pichia kudriavzevii strain VTT C-79090T to recombinantly express the D-xylose dehydrogenase coding gene from Caulobacter crescentus. With this single modification the recombinant strain VTT C-79090T produces up to 171 g/l of D-xylonate from 171 g/l D-xylose at a rate of 1.4 g/l/h and a high yield, which is comparable with D-xylonate production by Gluconobacter oxydans or Pseudomonas sp. The productivity of the strain is also remarkably high at low pH, producing 146 g/l D-xylonate at pH 3.0. Comparison to production of D-xylonate from Saccharomyces cerevisiae strain VTT B-67002 expressing the gene from Caulobacter crescentus, overview
both D-xylono-gamma-lactone and D-xylonate are produced when the Caulobacter crescentus gene xylB encoding D-xylose dehydrogenase is expressed in Saccharomyces cerevisiae, with or without co-expressionof xylC (D-xylonolactonase). XylC facilitates rapid opening of the lactone and more D-xylonate is initially produced than in its absence. In vivo [1H]NMR analysis of cell extracts, culture media and intact cells is used for analysis. The lactone and linear forms of D-xylonic acid are produced, accumulated intracellularly, and partially exported within 1560 min after D-xylose provision. Co-expression of xylB and xylC leads to rapid loss of pHluorin fluorescence and loss of vitality during production of D-xylonate. Loss of vitality in the presence of D-xylose is correlated to the extracellular pH, but fluorescence is lost from xylB and xylC expressing cells regardless of the extracellular condition. Method optimization, overview
engineering of non-conventional yeast Pichia kudriavzevii strain VTT C-79090T to recombinantly express the D-xylose dehydrogenase coding gene from Caulobacter crescentus. With this single modification the recombinant strain VTT C-79090T produces up to 171 g/l of D-xylonate from 171 g/l D-xylose at a rate of 1.4 g/l/h and a high yield, which is comparable with D-xylonate production by Gluconobacter oxydans or Pseudomonas sp. The productivity of the strain is also remarkably high at low pH, producing 146 g/l D-xylonate at pH 3.0. Comparison to production of D-xylonate from Saccharomyces cerevisiae strain VTT B-67002 expressing the gene from Caulobacter crescentus, overview
both D-xylono-gamma-lactone and D-xylonate are produced when the Caulobacter crescentus gene xylB encoding D-xylose dehydrogenase is expressed in Saccharomyces cerevisiae, with or without co-expressionof xylC (D-xylonolactonase). XylC facilitates rapid opening of the lactone and more D-xylonate is initially produced than in its absence. In vivo [1H]NMR analysis of cell extracts, culture media and intact cells is used for analysis. The lactone and linear forms of D-xylonic acid are produced, accumulated intracellularly, and partially exported within 1560 min after D-xylose provision. Co-expression of xylB and xylC leads to rapid loss of pHluorin fluorescence and loss of vitality during production of D-xylonate. Loss of vitality in the presence of D-xylose is correlated to the extracellular pH, but fluorescence is lost from xylB and xylC expressing cells regardless of the extracellular condition. Method optimization, overview
expression of gene xylB in Saccharomyces cerevisiae results in production of 17 g D-xylonate/l at 0.23g/l/h from 23 g D-xylose/l. D-Xylonate accumulates intracellularly to 70 mg/g, xylitol to 18 mg/g. Cells expressing D-xylonolactone lactonase xylC from Caulobacter crescentus with xylB initially produce more extracellular D-xylonate than cells lacking xylC at both pH5.5 and pH3, and sustain higher production at pH3. Cell vitality and viability decreases during D-xylonate production at pH 3.0
Toivari, M.; Nygard, Y.; Kumpula, E.P.; Vehkomaeki, M.L.; Bencina, M.; Valkonen, M.; Maaheimo, H.; Andberg, M.; Koivula, A.; Ruohonen, L.; Penttilae, M.; Wiebe, M.G.
Metabolic engineering of Saccharomyces cerevisiae for bioconversion of D-xylose to D-xylonate