Cellular responses to environmental salinity in the halophilic black yeast Hortaea werneckii

  title={Cellular responses to environmental salinity in the halophilic black yeast Hortaea werneckii},
  author={Urosˇ Petrovicˇ and Nina Gunde-Cimerman and Ana Plemenitasˇ},
  journal={Molecular Microbiology},
The development of crop plants with increased salt tolerance necessitates the study of naturally salt‐tolerant eukaryotic species. We studied the bio‐synthesis of glycerol as a compatible solute in the halophilic eukaryotic microorganism, black yeast Hortaea werneckii. A restriction fragment–differential display technique was used to investigate the transcriptome of the organism. Eight differentially expressed genes were identified in response to growth at different salinities. Although the… 

Ecology and molecular adaptations of the halophilic black yeast Hortaea werneckii

The black yeast Hortaea werneckii represents a new model organism for studying the mechanisms of salt tolerance in eukaryotes and the salt-dependent expressions of two HwENA genes suggest roles for them in the adaptation to changing salt concentrations.

Adaptation to high salt concentrations in halotolerant/halophilic fungi: a molecular perspective

The novel and intricate molecular mechanisms used by these fungi to combat high salt concentrations, which differ in many aspects between the extremely halotolerant H. werneckii and the halophilic W. ichthyophaga, are revealed.

Seven Years at High Salinity—Experimental Evolution of the Extremely Halotolerant Black Yeast Hortaea werneckii

W Whole-genome sequencing revealed the occurrence of multiple aneuploidies during the experimental evolution of the otherwise diploid H. werneckii, suggesting that long-term growth at extreme salinity led to alterations in cell wall and morphology, signalling pathways, and the pentose phosphate cycle.

Differential gene expression and Hog1 interaction with osmoresponsive genes in the extremely halotolerant black yeast Hortaea werneckii

Extremely halotolerant H. werneckii represents a suitable and highly relevant organism to study cellular responses to environmental salinity and shows a different set of genes being expressed at high salt concentrations and interacting with HwHog1 MAP kinase, suggesting atypical processes deserving of further study.

Osmotic adaptation of the halophilic fungus Hortaea werneckii: role of osmolytes and melanization.

It is hypothesize that H. werneckii melanization is effective in reducing the permeability of its cell wall to its major compatible solute glycerol, which might be one of the features that helps it tolerate a wider range of salt concentrations than most organisms.

Adaptation of extremely halotolerant black yeast Hortaea werneckii to increased osmolarity: a molecular perspective at a glance

Discovery of the black yeast Hortaea werneckii as the dominant fungal species in hypersaline waters enabled the introduction of a new model organism to study the mechanisms of salt tolerance in eukaryotes, and revealed novel, intricate mechanisms to combat fluctuating salinity.

Role of oxidative stress in the extremely salt-tolerant yeast Hortaea werneckii.

The ability of the extremely halotolerant black yeast Hortaea werneckii to combat oxidative stress was addressed, using hydrogen peroxide to generate the reactive oxygen species.

The MAP kinase HwHog1 from the halophilic black yeast Hortaea werneckii: coping with stresses in solar salterns

The HOG signalling pathway has an important role in sensing and responding to hyper-osmolar, oxidative and high-temperature stresses in the halophile fungi H. werneckii, a proposed model organism for studying the salt tolerance of halophilic and halotolerant eukaryotes.



Salt stress affects sterol biosynthesis in the halophilic black yeast Hortaea werneckii.

This work studied the regulation of sterol biosynthesis in H. werneckii through the activity and amount of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG R), a key regulatory enzyme in the biosynthesis of sterols.

Bioenergetic Aspects of Halophilism

  • A. Oren
  • Biology
    Microbiology and Molecular Biology Reviews
  • 1999
SUMMARY Examinination of microbial diversity in environments of increasing salt concentrations indicates that certain types of dissimilatory metabolism do not occur at the highest salinities.

Osmoregulation of the salt-tolerant yeast Debaryomyces hansenii grown in a chemostat at different salinities

The intracellular solute composition of the salt-tolerant yeast Debaryomyces hansenii was studied in glucose-limited chemostat cultures at different concentrations of NaCl (4 mM, 0.68 M, and 1.35 M).

Glycerol metabolism and osmoregulation in the salt-tolerant yeast Debaryomyces hansenii

A glycerol-nonutilizing mutant of the salt-tolerant yeast Debaryomyces hansenii was isolated, and at increased salinity the mutant showed a more pronounced decrease of growth rate and growth yield and lost more Glycerol to the surrounding medium than did the wild type.

Physiological basis for the high salt tolerance of Debaryomyces hansenii

It is proposed that the metabolism of D. hansenii is less sensitive to intracellular Na+ than is that of S. cerevisiae, that Na+ substitutes for K+ when K+ is scarce, and that the transport ofK+ is favored by the presence of Na+.

Physiology of osmotolerance in fungi.

Metabolic surprises in Saccharomyces cerevisiae during adaptation to saline conditions: questions, some answers and a model.

This review describes the metabolic alterations and adaptations of yeast cells in response to osmotic stress and hypothesised that the two pathways function as glycolytic safety valves during adaptation to stress.

Biology of Moderately Halophilic Aerobic Bacteria

The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms and approaches to the study of genetic processes have recently been developed, opening the way toward an understanding of haloadaptation at the molecular level.

Molecular cloning of the isoamyl alcohol oxidase-encoding gene (mreA) from Aspergillus oryzae.

GPD1, which encodes glycerol-3-phosphate dehydrogenase, is essential for growth under osmotic stress in Saccharomyces cerevisiae, and its expression is regulated by the high-osmolarity glycerol response pathway

Hog1 delta mutants lacking a protein kinase involved in osmostress-induced signal transduction failed to increase glycerol-3-phosphate dehydrogenase activity and mRNA levels when osmotic stress was imposed, suggesting the HOG pathway most probably has additional targets in the mechanism of adaptation to hypertonic medium.