Metabolic flux response to salt-induced stress in the halotoleirant yeast Debaryomyces hansenii

Neves, Maria Luísa Vieira das; Oliveira, Rui Pedro Soares de; Lucas, Cândida

doi:10.1099/00221287-143-4-1133

Cited by 58 publications

(61 citation statements)

References 14 publications

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“…hansenii (Neves et al, 1997). However, the level of resistance of any strain may also be temperature dependent (Trollmo et al, 1988 ;Prista & MadeiraLopes, 1995 ;Tokuoka, 1993) or pH dependent (Tokuoka, 1993).…”

Section: Discussionmentioning

confidence: 99%

Active glycerol uptake is a mechanism underlying halotolerance in yeasts: a study of 42 species

1999

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A comparison of 42 yeast species with respect to growth in the presence of high NaCl concentration and characteristics of glycerol uptake is presented. The yeast species were classified into four classes on the basis of their ability to grow in the presence of 1, 2, 3 or 4 M NaCl. Considering that two different types of active-transport systems for glycerol uptake have been described, Na M /glycerol and H M /glycerol symports, glycerol transport was investigated by testing for proton uptake upon glycerol addition in cells incubated in the absence and in the presence of NaCl. Only strains belonging to the two higher classes of salt tolerance showed constitutive active glycerol uptake, and could accumulate glycerol internally against a concentration gradient. Five of these strains exhibited a H M /glycerol symport. All the other strains showed evidence of the activity of a salt-dependent glycerol uptake similar to that described in the literature for Debraryomyces hansenii. The strains within the two lower classes of salt tolerance showed, to varying degrees, glycerol active uptake only when glycerol was used as the carbon and energy source, suggesting that this uptake system is involved in glycerol catabolism. The results within this work suggest that active glycerol uptake provides a basis for high halotolerance, helping to maintain a favourable intracellular concentration of glycerol. The relation between the constitutive expression of such carriers and a higher level of salt-stress resistance suggests that this may be an evolutionary advantage for growth under such conditions.

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Section: Discussionmentioning

confidence: 99%

Active glycerol uptake is a mechanism underlying halotolerance in yeasts: a study of 42 species

1999

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“…More than 30 years ago, it was reported that among several marine yeasts, D. hansenii was the least affected by high concentrations of NaCl (21,27). D. hansenii accumulates high amounts of Na ϩ , and in this yeast, Na ϩ is not more toxic than K ϩ (18,24,30). More recently it was shown that Na ϩ improves the performance of D. hansenii under different stress conditions (1).…”

Section: Two Genes Encoding Namentioning

confidence: 99%

Cloning and Expression of Two Genes Coding for Sodium Pumps in the Salt-Tolerant Yeast Debaryomyces hansenii

Almagro

Prista²,

Benito

et al. 2001

J Bacteriol

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Two genes encoding Na؉ -ATPases from Debaryomyces hansenii were cloned and sequenced. The genes, designated ENA1 from D. hansenii (DhENA1) and DhENA2, exhibited high homology with the corresponding genes from Schwanniomyces occidentalis. DhENA1 was expressed in the presence of high Na ؉ concentrations, while the expression of DhENA2 also required high pH. A mutant of Saccharomyces cerevisiae lacking the Na ؉ efflux systems and sensitive to Na ؉ , when transformed with DhENA1 or DhENA2, recovered Na ؉ tolerance and also the ability to extrude Na ؉ .

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“…The difference is not easily explainable. Other authors have used different media, in which the basal concentration of K + was lower, approximately 10 m by Norkrans (1966), and by Neves et al (1997). The main difference was that, instead of a mineral-defined medium, we used YPD medium without any addition, containing approximately 15 m of KCl.…”

Section: Transport Properties and Possible Mechanismsmentioning

confidence: 96%

“…At moderate concentrations of this salt, it can grow and carry out the main functions such as respiration and fermentation (Neves et al, 1997). Hobot and Jennings (1981) and Prista et al (1997) also observed that this yeast grows moderately better in the presence of moderate concentrations of NaCl.…”

Section: Introductionmentioning

confidence: 93%

Monovalent cation fluxes and physiological changes ofDebaryomyces hansenii grown at high concentrations of KCl and NaCl

Thomé‐Oritz

Peña

Ramı́rez

1998

Yeast

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Debaryomyces hansenii showed an increased growth in the presence of either 1m KCl or 1m NaCl and a low acidification of the medium, higher for the cells grown in the presence of NaCl. These cells accumulated high concentrations of the cations, and showed a very fast capacity to exchange either Na+ or K+ for the opposite cation. They showed a rapid uptake of 86 Rb+ and 22 Na+ . 86 Rb+ transport was saturable, with Km and Vmax values higher for cells grown in 1m NaCl. 22 Na+ uptake showed a diffusion component, also higher for the cells grown with NaCl. Changes depended on growth conditions, and not on further incubation, which changed the internal ion concentration. K+ stimulated proton pumping produced a rapid extrusion of protons, and also a decrease of the membrane potential. Cells grown in 1m KCl showed a higher fermentation rate, but significantly lower respiratory capacity. ATP levels were higher in cells grown in the presence of NaCl; upon incubation with glucose, those grown in the presence of KCl reached values similar to the ones grown in the presence of NaCl. In both, the addition of KCl produced a transient decrease of the ATP levels. As to ion transport mechanisms, D. hansenii appears to have (a) an ATPase functioning as a proton pump, generating a membrane potential difference which drives K+ through a uniporter; (b) a K+ /H+ exchange system; and (c) a rapid cation/cation exchange system. Most interesting is that cells grown in different ionic environments change their studied capacities, which are not dependent on the cation content, but on differences in their genetic expression during growth. © 1998 John Wiley & Sons, Ltd.

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Metabolic flux response to salt-induced stress in the halotoleirant yeast Debaryomyces hansenii

Cited by 58 publications

References 14 publications

Active glycerol uptake is a mechanism underlying halotolerance in yeasts: a study of 42 species

Active glycerol uptake is a mechanism underlying halotolerance in yeasts: a study of 42 species

Cloning and Expression of Two Genes Coding for Sodium Pumps in the Salt-Tolerant Yeast Debaryomyces hansenii

Monovalent cation fluxes and physiological changes ofDebaryomyces hansenii grown at high concentrations of KCl and NaCl

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