Affiliation:
1. Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, Indiana 47907-1295
Abstract
ABSTRACT
Xylose is one of the major fermentable sugars present in cellulosic biomass, second only to glucose. However,
Saccharomyces
spp., the best sugar-fermenting microorganisms, are not able to metabolize xylose. We developed recombinant plasmids that can transform
Saccharomyces
spp. into xylose-fermenting yeasts. These plasmids, designated pLNH31, -32, -33, and -34, are 2μm-based high-copy-number yeast-
E. coli
shuttle plasmids. In addition to the geneticin resistance and ampicillin resistance genes that serve as dominant selectable markers, these plasmids also contain three xylose-metabolizing genes, a xylose reductase gene, a xylitol dehydrogenase gene (both from
Pichia stipitis
), and a xylulokinase gene (from
Saccharomyces cerevisiae
). These xylose-metabolizing genes were also fused to signals controlling gene expression from
S. cerevisiae
glycolytic genes. Transformation of
Saccharomyces
sp. strain 1400 with each of these plasmids resulted in the conversion of strain 1400 from a non-xylose-metabolizing yeast to a xylose-metabolizing yeast that can effectively ferment xylose to ethanol and also effectively utilizes xylose for aerobic growth. Furthermore, the resulting recombinant yeasts also have additional extraordinary properties. For example, the synthesis of the xylose-metabolizing enzymes directed by the cloned genes in these recombinant yeasts does not require the presence of xylose for induction, nor is the synthesis repressed by the presence of glucose in the medium. These properties make the recombinant yeasts able to efficiently ferment xylose to ethanol and also able to efficiently coferment glucose and xylose present in the same medium to ethanol simultaneously.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference27 articles.
1. Expression of genes in yeast using the ADC1 promoter;Ammerer G.;Methods Enzymol.,1983
2. Armstrong
K. A.
Som
T.
Volkert
F. C.
Rose
A.
Broach
J. R.
(1989) Propagation and expression of genes in yeast using 2-micron circle vectors. in Yeast genetic engineering. eds BarrP. J.BrakeA. J.ValenzuelaP. (Butterworths Boston Mass) pp 165–192.
3. High efficiency transformation of yeast by electroporation;Becker D.;Methods Enzymol.,1991
4. The primary structure of the Saccharomyces cerevisiae gene for alcohol dehydrogenase I;Bennetzen J. L.;J. Biol. Chem.,1982
5. Induction of NADPH-linked d-xylose reductase and NAD-linked xylitol dehydrogenase activities in Pachysolen tannophilus by d-xylose, l-arabinose, or d-galactose;Bolen P. L.;Biotechnol. Bioeng.,1985
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