scholarly journals Expression of xylitol dehydrogenase gene xyl2 in Saccharomyces cerevisiae

2018 ◽  
Author(s):  
Hongyuan Huang
2009 ◽  
Vol 75 (11) ◽  
pp. 3818-3822 ◽  
Author(s):  
Akinori Matsushika ◽  
Hiroyuki Inoue ◽  
Seiya Watanabe ◽  
Tsutomu Kodaki ◽  
Keisuke Makino ◽  
...  

ABSTRACT The recombinant industrial Saccharomyces cerevisiae strain MA-R5 was engineered to express NADP+-dependent xylitol dehydrogenase using the flocculent yeast strain IR-2, which has high xylulose-fermenting ability, and both xylose consumption and ethanol production remarkably increased. Furthermore, the MA-R5 strain produced the highest ethanol yield (0.48 g/g) from nonsulfuric acid hydrolysate of wood chips.


2010 ◽  
Vol 2 (2) ◽  
pp. 351-361
Author(s):  
A. A. Saleh ◽  
S. Hamdan ◽  
N. Annaluru ◽  
S. Watanabe ◽  
M. R. Rahman ◽  
...  

Agricultural waste biomass has already been transferred to bioethanol and used as energy related products, although many issues such as efficiency and productivity still to be overcome. In this study, the protein engineering was applied to generate enzymes with completely reversed coenzyme specificity and developed recombinant yeasts containing those engineered enzymes for construction of an efficient biomass-ethanol conversion system. Recombinant yeasts were constructed with the genes encoding a wild type xylose reductase (XR) and the protein engineered xylitol dehydrogenase (XDH) (with NADP) of Pichia stipitis.  These recombinant yeasts were characterized based on the enzyme activity and fermentation ability of xylose to ethanol. The protein engineered enzymes were expressed significantly in Saccharomyces cerevisiae as judged by the enzyme activity in vitro. Ethanol fermentation was measured in batch culture under anaerobic conditions. The significant enhancement was found in Y-ARS strain, in which NADP+-dependent XDH was expressed; 85% decrease of unfavorable xylitol excretion with 26% increased ethanol production, when compared with the reference strain expressing the wild-type XDH.  Keywords: Agricultural waste biomass; Protein engineering; Xylitol dehydrogenase; Xylose-fermentation; Eethanol production. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.2882               J. Sci. Res. 2 (2), 351-361 (2010) 


1987 ◽  
Vol 7 (2) ◽  
pp. 813-820
Author(s):  
M J Holland ◽  
T Yokoi ◽  
J P Holland ◽  
K Myambo ◽  
M A Innis

The intracellular concentrations of the polypeptides encoded by the two enolase (ENO1 and ENO2) and three glyceraldehyde-3-phosphate dehydrogenase (TDH1, TDH2, and TDH3) genes were coordinately reduced more than 20-fold in a Saccharomyces cerevisiae strain carrying the gcr1-1 mutation. The steady-state concentration of glyceraldehyde-3-phosphate dehydrogenase mRNA was shown to be approximately 50-fold reduced in the mutant strain. Overexpression of enolase and glyceraldehyde-3-phosphate dehydrogenase in strains carrying multiple copies of either ENO1 or TDH3 was reduced more than 50-fold in strains carrying the gcr1-1 mutation. These results demonstrated that the GCR1 gene encodes a trans-acting factor which is required for efficient and coordinate expression of these glycolytic gene families. The GCR1 gene and the gcr1-1 mutant allele were cloned and sequenced. GCR1 encodes a predicted 844-amino-acid polypeptide; the gcr1-1 allele contains a 1-base-pair insertion mutation at codon 304. A null mutant carrying a deletion of 90% of the GCR1 coding sequence and a URA3 gene insertion was constructed by gene replacement. The phenotype of a strain carrying this null mutation was identical to that of the gcr1-1 mutant strain.


2007 ◽  
Vol 73 (17) ◽  
pp. 5471-5476 ◽  
Author(s):  
Mervi H. Toivari ◽  
Laura Ruohonen ◽  
Andrei N. Miasnikov ◽  
Peter Richard ◽  
Merja Penttilä

ABSTRACT Recombinant Saccharomyces cerevisiae strains that produce the sugar alcohols xylitol and ribitol and the pentose sugar d-ribose from d-glucose in a single fermentation step are described. A transketolase-deficient S. cerevisiae strain accumulated d-xylulose 5-phosphate intracellularly and released ribitol and pentose sugars (d-ribose, d-ribulose, and d-xylulose) into the growth medium. Expression of the xylitol dehydrogenase-encoding gene XYL2 of Pichia stipitis in the transketolase-deficient strain resulted in an 8.5-fold enhancement of the total amount of the excreted sugar alcohols ribitol and xylitol. The additional introduction of the 2-deoxy-glucose 6-phosphate phosphatase-encoding gene DOG1 into the transketolase-deficient strain expressing the XYL2 gene resulted in a further 1.6-fold increase in ribitol production. Finally, deletion of the endogenous xylulokinase-encoding gene XKS1 was necessary to increase the amount of xylitol to 50% of the 5-carbon sugar alcohols excreted.


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