Search for dissertations about: "XR"

Showing result 6 - 10 of 23 swedish dissertations containing the word XR.

2. 6. Engineering xylose and arabinose metabolism in recombinant Saccharomyces cerevisiae

   Author : Kaisa Karhumaa; Teknisk mikrobiologi; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; virologi; bakteriologi; mycology; Mikrobiologi; bacteriology; Saccharomyces cerevisiae ; arabinose; xylose; fermentation; lignocellulose; yeast; mykologi; Biochemical technology; Biokemisk teknik; virology; Microbiology; ethanol;

   Abstract : Utilization of all sugars in lignocellulose hydrolysates is a prerequisite for economically feasible bioethanol production. The yeast commonly used for industrial ethanol production, Saccharomyces cerevisiae, is naturally unable to utilize pentose sugars xylose and arabinose, which constitute a large fraction of many lignocellulosic materials. READ MORE

4. 7. Genetic Traits Beneficial for Xylose Utilization by Recombinant Saccharomyces cerevisiae

   Author : Oskar Bengtsson; Teknisk mikrobiologi; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Saccharomyces cerevisiae; metabolic engineering; fermentation; xylose; ethanol; promoter; xylose reductase; cofactor; validation; transcriptome;

   Abstract : Saccharomyces cerevisiae ferments hexoses in lignocellulosic hydrolysates under anaerobic conditions with high rates and ethanol yields. However, S. cerevisiae is naturally unable to utilize the pentose fraction of the hydrolysates. Xylose is the most abundant pentose sugar, and although recombinant S. READ MORE

5. 8. Redox balancing in recombinant strains of Saccharomyces cerevisiae

   Author : Mikael Anderlund; Teknisk mikrobiologi; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; xylose isomerase; xylitol dehydrogenase; xylose reductase; glycerol; xylitol; xylose; E. coli; A. vinelandii; T. thermophilus; S. cerevisiae; P. stipitis; transhydrogenase.; Microbiology; bacteriology; virology; mycology; Mikrobiologi; bakteriologi; virologi; mykologi;

   Abstract : In metabolically engineered Saccharomyces cerevisiae expressing Pichia stipitis XYL1 and XYL2 genes, encoding xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, xylitol is excreted as the major product during anaerobic xylose fermentation and only low yields of ethanol are produced. This has been interpreted as a result of the dual cofactor dependence of XR and the exclusive use of NAD+ by XDH. READ MORE

6. 9. Engineering Saccharomyces cerevisiae for mixed-sugar fermentation

   Author : Rosa Garcia Sanchez; Teknisk mikrobiologi; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; metabolic engineering; evolutionary engineering; promoter; mixed-sugar utilization; galactose; arabinose; xylose; Saccharomyces cerevisiae; fermentation; ethanol; phosphoglucomutase;

   Abstract : Efficient fermentation of all the monomeric sugars derived from lignocellulose is crucial to increase the economy of bioethanol production, since they can account for a considerable fraction of the fermentable sugars in the raw material. This thesis describes the engineering of Saccharomyces cerevisiae strains for improved xylose, galactose and/or arabinose utilization. READ MORE

7. 10. Improving initial xylose metabolism in recombinant Saccharomyces cerevisiae

   Author : Márk Gárdonyi; Teknisk mikrobiologi; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biokemisk teknik; Biochemical technology; xylose isomerase; xylose transport; xylose fermentation; Saccharomyces cerevisiae; metabolic engineering;

   Abstract : The aim of the thesis is to improve the initial steps of xylose metabolism in recombinant Saccharomyces cerevisiae. S. cerevisiae takes up xylose of poor affinity by means of hexose transporters. Metabolic control analysis was used to investigate whether the low xylose utilisation rate is due to inefficient transport. READ MORE