Xylose utilization by recombinant yeasts
First Claim
1. A process for producing xylitol, which process comprises:
- (a) cultivating in a xylose-containing medium a yeast strain selected from the group consisting of Saccharomyces spp., a Kluyveromyces spp. and a Schizosaccharomyces spp., transformed with a DNA molecule encoding a xylose reductase enzyme of a yeast or a mold, which DNA molecule, when transformed into said yeast strain, confers to said yeast strain the ability of reducing xylose to xylitol; and
(b) recovering xylitol formed from the medium.
1 Assignment
0 Petitions
Accused Products
Abstract
This invention relates to recombinant-DNA-technology. Specifically, this invention relates to new recombinant yeast strains transformed with xylose reductase and/or xylitol dehydrogenase enzyme genes. A yeast strain transformed with the xylose reductase gene is capable of reducing xylose to xylitol and consequently of producing xylitol in vivo. If both of these genes are transformed into a yeast strain, the resultant strain is capable of producing ethanol on xylose containing medium during fermentation. Further, the said new yeast strains are capable of expressing the said two enzymes. Xylose reductase produced by these strains can be used in an enzymatic process for the production of xylitol in vitro.
63 Citations
15 Claims
-
1. A process for producing xylitol, which process comprises:
-
(a) cultivating in a xylose-containing medium a yeast strain selected from the group consisting of Saccharomyces spp., a Kluyveromyces spp. and a Schizosaccharomyces spp., transformed with a DNA molecule encoding a xylose reductase enzyme of a yeast or a mold, which DNA molecule, when transformed into said yeast strain, confers to said yeast strain the ability of reducing xylose to xylitol; and (b) recovering xylitol formed from the medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A process for producing xylulose, which process comprises:
(a) cultivating in a xylose-containing medium a yeast strain selected from the group consisting of Saccharomyces spp., a Kluyveromyces spp. and a Schizosaccharomyces spp., transformed with a DNA molecule encoding a xylose reductase enzyme of a yeast or a mold, which DNA molecule, when transformed into said yeast strain, confers the ability to said yeast strain of reducing xylose to xylitol; and
wherein said transformed yeast strain is further transformed with a second DNA molecule encoding a xylitol dehydrogenase enzyme of a yeast or a mold, which second DNA molecule, when transformed into said transformed yeast, confers to said yeast the ability to convert xylitol to xylulose.- View Dependent Claims (10, 11, 12, 13, 14)
-
15. A process for producing xylitol, which process comprises:
-
(a) cultivating in a xylose-containing medium a yeast strain selected from the group consisting of Saccharomvces spp., a Kluyveromyces spp and a Schizosaccharomyces spp., transformed with a DNA molecule encoding a xylose reductase enzyme, which DNA molecule, when transformed into said yeast strain, confers to said yeast strain the ability of reducing xylose to xylitol; and (b) recovering xylitol formed from the medium;
wherein said DNA molecule has a nucleotide sequence of DNA encoding a xylose reductase enzyme of an organism being a Candida spp., an Enterobacter spp., a Corynebacterium spp., a Kluyveromyces spp., a Pichia spp., Pachysolen tannophilus or Penicillium chrysogenum.
-
Specification