Xylitol Production by Recombinant Saccharomyces Cerevisiae

Hallborn, Johan; Walfridsson, Mats; Airaksinen, Ulla; Ojamo, Heikki; Hahn‐Hägerdal, Bärbel; Penttilä, Merja; Keränen, Sirkka

doi:10.1038/nbt1191-1090

Cited by 193 publications

(103 citation statements)

References 28 publications

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“…The gene encodes a xylose reductase. 47 Toxins Mycotoxins, which are poisons produced by fungi, have actually been useful therapeutic agents for a variety of medical conditions and ailments. These agents (for example, ergot alkaloids) had caused fatal poisoning of humans and animals (ergotism) for centuries by consumption of bread made from grain contaminated with species of the fungus Claviceps.…”

Section: Prebioticsmentioning

confidence: 99%

Production of valuable compounds by molds and yeasts

Demain

Martens

2016

J Antibiot

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where he has contributed in a major way to the reputation of this department for many years. He also served as an Adjunct Professor at the University of Geneva. Among Julian's areas of study and accomplishment are fungal toxins including α-sarcin, chemical synthesis of triterpenes, mode of action of streptomycin and other aminoglycoside antibiotics, biochemical mechanisms of antibiotic resistance in clinical isolates of bacteria harboring resistance plasmids, their origins and evolution, secondary metabolism of microorganisms, structure and function of bacterial ribosomes, antibiotic resistance mutations in yeast ribosomes, cloning of resistance genes from an antibiotic-producing microbe, gene cloning for industrial purposes, engineering of herbicide resistance in useful crops, bleomycin-resistance gene in clinical isolates of Staphylococcus aureus and many other topics. He has been an excellent teacher, lecturing in both English and French around the world, and has organized international courses. Julian has also served on the NIH study sections, as Editor for several international journals, and was one of the founders of the journal Plasmid. We expect the impact of Julian's accomplishments to continue into the future.

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Section: Prebioticsmentioning

confidence: 99%

Production of valuable compounds by molds and yeasts

Demain

Martens

2016

J Antibiot

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“…The strain S. cerevisiae H475 [strain H158: obtained from Gregg Payne, University of California, Berkeley, containing the plasmid pUA103 (Hallborn et al, 1991)], was maintained on selective SC-leu (Sherman et al, 1983) agar plates. The X Y L l gene on pUA103 is regulated by the constitutive phosphoglycerate kinase promoter (Mellor e t al., 1983).…”

Section: Methodsmentioning

confidence: 99%

A heterologous reductase affects the redox balance of recombinant Saccharomyces cerevisiae

Meinander¹,

Zacchi

Hahn‐Hägerdal³

1996

Microbiology

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Recombinant Sacchammyces cerevisiae harbouring the xylose reductase (XR) gene XYLl from Pichia stipitis was grown in anoxic chemostat culture at two different dilution rates. At each dilution rate a transient experiment, encompassing a shift in the sugar content of the medium from glucose to glucose plus xylose was performed. The steady states at the beginning and the end of the transients were compared in terms of specific product fluxes from glucose metabolism. A t both dilution rates, the specific glycerol flux decreased and the specific acetate and CO, fluxes increased. The specific ethanol flux was not affected. At the lower dilution rate, the production of biomass decreased during the transient, but at the higher dilution rate it increased. The changes in product pattern can be explained as being due to the redox perturbation caused by the consumption of reduced cofactors in the XR-catalysed reaction. Regeneration of NAD partly through xylose reduction instead of glycerol production decreased the formation of glycerol. Additionally, xylose reduction activated those pathways which produce reduced cofactors, such as acetate formation and the pentose phosphate pathway, indicated by increased acetate and CO, production. The dual cofactor specificity of XR, with a preference for NADPH over NADH, was evident from the effects of xylose reduction on product fluxes. Comparison of the xylose reduction rates at low and high glucose flux indicated that the supply of reduced cofactors partly controlled the reaction rate. At the higher dilution rate, control by some other factor such as xylose transport or XR activity increased. Calculation of carbon balances at the steady states showed that all substrate carbon was recovered in biomass or products. Based on the specific product fluxes, calculations of quantitative cofactor balances at the steady states was attempted. However, sensitivity calculations showed that analysis errors in the range of 5% caused substantial errors in the cofactor balance, without affecting the carbon balance.

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“…Hence, fuel ethanol production from pentose-rich sources, such as hardwood or agricultural residues will only be economically viable if xylose is fermented to ethanol (Hinman et al, 1989;Von Sivers and Zacchi, 1996). The genes necessary for xylose metabolism have been cloned and expressed in S. cerevisiae (Hallborn, et al, 1991;Ho and Chang, 1989;Kötter et al, 1990;Tantirungki, et al, 1993). The resulting strains were capable of utilizing xylose, but they compared poorly with natural xylose utilizing yeasts, like Pichia stipitis, in terms of growth rate and ethanol productivity (Kötter and Ciriacy, 1993;Wahlbom, 2002).…”

Section: Introductionmentioning

confidence: 99%