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Hortaea werneckii is a species of yeast in the family Teratosphaeriaceae.[1] It is a black yeast that is investigated for its remarkable halotolerance.[2][3] While the addition of salt to the medium is not required for its cultivation, H. werneckii can grow in close to saturated NaCl solutions.[4] To emphasize this unusually wide adaptability, and to distinguish H. werneckii from other halotolerant fungi, which have lower maximum salinity limits, some authors describe H. werneckii as "extremely halotolerant".[4]
Several salt-tolerance mechanisms of H. werneckii have been studied on molecular level.[4] For example, it is known that its major compatible solutes are glycerol, erythritol, arabitol, and mannitol; melanin accumulation of the cell wall aids in retention of at least glycerol inside of the cell.[3] Several components of the high osmolarity glycerol (HOG) signalling pathway (which controls responses to osmotic shock) have been studied in detail and some seem to differ in function compared to their counterparts in Saccharomyces cerevisiae.[5][6][7] Adaptation to high concentrations of salt are also accompanied by changes in membrane lipid composition, mainly by increasing the unsaturation of the phospholipid fatty acids.[8][9]
H. werneckii causes a rare superficial and non-invasive skin infection Tinea nigra.[10] The typical symptoms are non-scaly, smooth, brown-black painless spots on the palms of hands and soles of feet.
The growth of H. werneckii in liquid media is often yeast-like, although it can switch to filamentous growth. The mechanism of the switch is not known. The cells appear brown because of melanin production.[3]
Whole genome sequencing of H. werneckii[11][12] revealed a recent whole genome duplication, thought to be the only reported whole-genome duplication among ascomycetous yeasts besides the better known one in the Saccharomyces cerevisiae lineage.[13] Based on genome sequencing of additional strains, 10 out of 12 strains have a genome that was duplicated by several hybridizations between haploid strains, yielding formed stable diploids. Apart from these hybridization events, no signs of sexual reproduction were found.[14] As a consequence, the genome of H. werneckii is relatively large (49.9 Mb) with 15974 predicted genes.[12] Genes encoding metal cation transporters, which are thought to play a role in halotolerance, experienced several additional gene duplications at various points during their evolution.[11]
A homothallic mating locus was found in all sequenced genomes, although one of the mating genes may have been inactivated in some strains. Despite this, phylogenetic analyses and linkage disequilibrium analyses indicate that H. werneckii is asexual.[14]
Hortaea werneckii is a species of yeast in the family Teratosphaeriaceae. It is a black yeast that is investigated for its remarkable halotolerance. While the addition of salt to the medium is not required for its cultivation, H. werneckii can grow in close to saturated NaCl solutions. To emphasize this unusually wide adaptability, and to distinguish H. werneckii from other halotolerant fungi, which have lower maximum salinity limits, some authors describe H. werneckii as "extremely halotolerant".
Several salt-tolerance mechanisms of H. werneckii have been studied on molecular level. For example, it is known that its major compatible solutes are glycerol, erythritol, arabitol, and mannitol; melanin accumulation of the cell wall aids in retention of at least glycerol inside of the cell. Several components of the high osmolarity glycerol (HOG) signalling pathway (which controls responses to osmotic shock) have been studied in detail and some seem to differ in function compared to their counterparts in Saccharomyces cerevisiae. Adaptation to high concentrations of salt are also accompanied by changes in membrane lipid composition, mainly by increasing the unsaturation of the phospholipid fatty acids.
H. werneckii causes a rare superficial and non-invasive skin infection Tinea nigra. The typical symptoms are non-scaly, smooth, brown-black painless spots on the palms of hands and soles of feet.
The growth of H. werneckii in liquid media is often yeast-like, although it can switch to filamentous growth. The mechanism of the switch is not known. The cells appear brown because of melanin production.
Whole genome sequencing of H. werneckii revealed a recent whole genome duplication, thought to be the only reported whole-genome duplication among ascomycetous yeasts besides the better known one in the Saccharomyces cerevisiae lineage. Based on genome sequencing of additional strains, 10 out of 12 strains have a genome that was duplicated by several hybridizations between haploid strains, yielding formed stable diploids. Apart from these hybridization events, no signs of sexual reproduction were found. As a consequence, the genome of H. werneckii is relatively large (49.9 Mb) with 15974 predicted genes. Genes encoding metal cation transporters, which are thought to play a role in halotolerance, experienced several additional gene duplications at various points during their evolution.
A homothallic mating locus was found in all sequenced genomes, although one of the mating genes may have been inactivated in some strains. Despite this, phylogenetic analyses and linkage disequilibrium analyses indicate that H. werneckii is asexual.
Hortaea werneckii, antigamente chamado de Exophiala werneckii, é uma levedura comum no meio ambiente, mas causa tinea nigra, ao produzir uma camada de melanina na pele de seres humanos. Pode ser encontrado no solo, lagos, oceano, plantas e madeira em regiões tropicais e sub-tropicais úmidas. É extremamente resistente a altas concentrações de sal, modificando sua membrana celular e criando uma camada de melanina para reter os componentes essenciais para suas células. [1]
Tinea nigra(tinha negra) é uma infecção fúngica superficial caracterizada por máculas (manchas) marrom ou negras, geralmente nas palmas das mãos ou plantas dos pés, e ocasionalmente em outras superfícies da pele. As manchas não são inflamatórias, não coçam, não invadem a pele e não doem, são apenas um problema estético. Podem ser transmitidas pelo contato físico ou por tecidos compartilhados. Podem ser tratados com pomadas de cetoconazol ou outro derivado do imidazol.[2]
Hortaea werneckii, antigamente chamado de Exophiala werneckii, é uma levedura comum no meio ambiente, mas causa tinea nigra, ao produzir uma camada de melanina na pele de seres humanos. Pode ser encontrado no solo, lagos, oceano, plantas e madeira em regiões tropicais e sub-tropicais úmidas. É extremamente resistente a altas concentrações de sal, modificando sua membrana celular e criando uma camada de melanina para reter os componentes essenciais para suas células.
Hortaea werneckii je grzib[6], co go nojprzōd ôpisoł Horta, a terŏźnõ nazwã doł mu Nishim. & Miyaji 1984. Hortaea werneckii nŏleży do zorty Hortaea i familije Teratosphaeriaceae.[7][8] Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.[7]
Hortaea werneckii je grzib, co go nojprzōd ôpisoł Horta, a terŏźnõ nazwã doł mu Nishim. & Miyaji 1984. Hortaea werneckii nŏleży do zorty Hortaea i familije Teratosphaeriaceae. Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.
威尼克外瓶黴（Exophiala werneckii[2][3]，舊稱Hortaea werneckii）是一種會分泌黑色素的外瓶黴屬真菌，是黑癬的病原體[4] 。原屬Hortaea屬[5]。 部份文獻把這種黴與 Hortaea werneckii、Cladosporium werneckii及Phaeoannellomyces werneckii等同[6]。
