''Debaryomyces hansenii'', also known as ''Candida famata'', is a species of

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

in the family

Saccharomycetaceae The Saccharomycetaceae are a family of yeasts in the order Saccharomycetales that reproduce by budding. Species in the family have a cosmopolitan distribution, and are present in a wide variety of habitats, especially those with a plentiful supp ...

Pathogenicity

''Debaryomyces hansenii'' accounts for up to 2% of invasive

candidiasis Candidiasis is a fungal infection due to any species of the genus '' Candida'' (a yeast). When it affects the mouth, in some countries it is commonly called thrush. Signs and symptoms include white patches on the tongue or other areas of the ...

cases. It has been found in Crohn's disease ulcerations in humans and is being investigated as the environmental trigger of Crohn's disease. Certain strains of ''Debaryomyces hansenii'' have been researched for potential use as probiotics and may have health benefits.

Ecology

''Debaryomyces hansenii'' is an osmo-, halo- and xerotolerant

that produces toxins, including mycocins, to destroy competitive yeast species. It is a common species in all types of cheese, including soft cheeses and the brines of semi-hard and hard cheeses, and the most common yeast among 383 isolates from samples of unsulfited or sulfited sausages, skinless sausages and minced beef. It contributes to the fermentation of

barrel-aged beer A barrel-aged beer is a beer that has been aged for a period of time in a wooden barrel. Typically, these barrels once housed bourbon, whisky, wine, or, to a lesser extent, brandy, sherry, or port.Imperial Stout Stout is a type of dark beer that is generally warm fermented, such as dry stout, oatmeal stout, milk stout and imperial stout. Stout is a type of ale. The first known use of the word "stout" for beer is in a document dated 1677 in the E ...

from

Harveys Brewery Harvey's Brewery is a brewery in Lewes, East Sussex, England. Harvey's estate includes 45 tied houses, mostly in Sussex, and three in London: Royal Oak, Southwark, The Cat's Back, Wandsworth and The Phoenix, Stockwell. It sells and distribu ...

in southern England. Harvey's head brewer speculates that it is either airborne in the brewery or a slow-growing component of their house yeast blend. ''D. hansenii'' is also found in hyper-saline waters such as the

saltern A saltern is an area or installation for making salt. Salterns include modern salt-making works (saltworks), as well as hypersaline waters that usually contain high concentrations of Halophile, halophilic microorganisms, primarily haloarchaea but ...

s on the Atlantic coast of

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

or in the

Great Salt Lake The Great Salt Lake is the largest saltwater lake in the Western Hemisphere and the eighth-largest terminal lake in the world. It lies in the northern part of the U.S. state of Utah and has a substantial impact upon the local climate, partic ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

Nutritional requirements

The species can be cultivated in media with up to 25%

NaCl Sodium chloride , commonly known as edible salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. It is transparent or translucent, brittle, hygroscopic, and occurs as the mineral hali ...

or 18%

glycerol Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...

. Growth rate increases in solutions with ≥ 1 M NaCl or KCl, with sodium and potassium ions playing a very important role in the mechanisms involved in maintaining osmobalance. The species can survive a pH range between 3 and 10. Furthermore, ''D. hansenii'' has been described as the species with the highest

perchlorate A perchlorate is a chemical compound containing the perchlorate ion, , the conjugate base of perchloric acid (ionic perchlorate). As counterions, there can be metal cations, quaternary ammonium cations or other ions, for example, nitronium cat ...

tolerance reported to date, which might have consequences for the microbial habitability of

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

, where perchlorate salts are widely distributed.

Reproduction

Most strains are

haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...

, mating very rarely and

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

ize transiently by somatogamous

autogamy Autogamy or self-fertilization refers to the Cell fusion, fusion of two gametes that come from one individual. Autogamy is predominantly observed in the form of self-pollination, a Reproduction, reproductive mechanism employed by many flowering pl ...

(i.e. fusion of two cells but excluding their nuclei). Sexual reproduction proceeds via

heterogamous Heterogamy is a term applied to a variety of distinct phenomena in different scientific domains. Usually having to do with some kind of difference, "hetero", in reproduction, "gamy". See below for more specific senses. Science Reproductive biolog ...

conjugation (i.e. the conjugation of two cells of different form or size) leading to short diplophase followed by

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

and

ascospore In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...

formation. Haploid yeasts reproduce

vegetatively Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is a form of asexual reproduction occurring in plants in which a new plant grows from a fragment or Cutting (plant), cutting of the parent pl ...

by multilateral budding.

Genetics

This species has seven chromosomes, labeled A-G. This species uses an alternative genetic code for the codon CUG, coding for the amino acid serine instead of the usual leucine.

Differentiation

The ability of this species to grow at 10% NaCl or 5% glucose is used to discriminate ''D. hansenii'' from other ascomycetous yeasts. The species comprises two

varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

: ''D. hansenii'' var. ''hansenii'' and var. ''fabryii''. These two groups can be differentiated via

rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

, the

electrophoretic mobility Electrophoresis is the motion of charged dispersed particles or dissolved charged molecules relative to a fluid under the influence of a spatially uniform electric field. As a rule, these are zwitterions with a positive or negative net ch ...

of their

glucose-6-phosphate dehydrogenase Glucose-6-phosphate dehydrogenase (G6PD or G6PDH) () is a cytosolic enzyme that catalysis, catalyzes the chemical reaction : Glucose 6-phosphate, D-glucose 6-phosphate + NADP+ + 6-Phosphogluconolactone, 6-phospho-D-glucono-1,5-lactone + NADPH ...

, or by their maximum grow temperatures (35 °C for var. ''hansenii'' and 39 °C for var. ''fabryii'').

Biotechnology

The species has been demonstrated to synthesize useful quantities of

D-arabinitol Arabitol, or arabinitol, is a sugar alcohol. It can be formed by the reduction of either arabinose or lyxose. Some organic acid tests check for the presence of D-arabitol, which may indicate overgrowth of intestinal microbes such as ''Candida alb ...

riboflavin Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in ...

xylitol Xylitol is a chemical compound with the formula , or HO(CH2)(CHOH)3(CH2)OH; specifically, one particular Stereoisomerism, stereoisomer with that structural formula. It is a colorless or white crystalline solid. It is classified as a polyalcoho ...

, and

pyruvic acid Pyruvic acid (CH3COCOOH) is the simplest of the keto acids, alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate acid, conjugate base, CH3COCOO−, is an metabolic intermediate, intermediate in several m ...

under thiamine limitation. The species has also been used to

decarboxylate Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is ...

ferulic acid Ferulic acid is a hydroxycinnamic acid derivative and a phenolic compound. It is an organic compound with the formula (CH3O)HOC6H3CH=CHCO2H. The name is derived from the genus '' Ferula'', referring to the giant fennel ('' Ferula communis''). Cl ...

2-Methoxy-4-vinylphenol 2-Methoxy-4-vinylphenol is an aromatic substance used as a flavoring agent. It is one of the compounds responsible for the natural aroma of buckwheat. Some insects such as ''Rhynchophorus ferrugineus'' (Red palm weevil) use this substance for che ...

via

biotransformation Biotransformation is the biochemical modification of one chemical compound or a mixture of chemical compounds. Biotransformations can be conducted with whole cells, their lysates, or purified enzymes. Increasingly, biotransformations are effected ...

(a 95.07% yield, 1470.8 mg/L, within 10 hours).

References

External links

* {{Taxonbar, from=Q10467497 Food microbiology Fungi described in 1889 Yeasts Osmophiles Halophiles Xerophiles Saccharomycetaceae Taxa named by Friedrich Wilhelm Zopf Fungus species