{{Short description|Species of fungus}} {{Speciesbox | image = Debaryomyces_hansenii_5-1-6_(Sidari_2021).jpg | taxon = Debaryomyces hansenii | authority = (Zopf) Lodder & Kreger-van Rij (1984) | synonyms = *''Saccharomyces hansenii'' <small>Zopf (1889)</small> }}
'''''Debaryomyces hansenii''''', also known as '''''Candida famata''''', is a species of yeast in the family Saccharomycetaceae.
==Pathogenicity== ''Debaryomyces hansenii'' accounts for up to 2% of invasive candidiasis cases.<ref>{{cite journal | vauthors = Beyda ND, Chuang SH, Alam MJ, Shah DN, Ng TM, McCaskey L, Garey KW |display-authors=3| title = Treatment of Candida famata bloodstream infections: case series and review of the literature | journal = The Journal of Antimicrobial Chemotherapy | volume = 68 | issue = 2 | pages = 438–443 | date = February 2013 | pmid = 23085777 | doi = 10.1093/jac/dks388 | doi-access = free }}</ref> It has been found in Crohn's disease ulcerations in humans and is being investigated as the environmental trigger of Crohn's disease.<ref name="Reynolds2021">{{cite web |last=Reynolds |first=Sharon |title=Fungi may impair wound healing in Crohn's disease | website=National Institutes of Health (NIH) | date=March 29, 2021 | url=https://www.nih.gov/news-events/nih-research-matters/fungi-may-impair-wound-healing-crohns-disease | access-date=January 27, 2023}}</ref><ref name=" Jain2021">{{cite journal |vauthors=Jain U, Ver Heul AM, Xiong S, Gregory MH, Demers EG, Kern JT, Lai CW, Muegge BD, Barisas D, Leal-Ekman JS, Deepak P, Ciorba MA, Liu TC, Hogan DA, Debbas P, Braun J, McGovern D, Underhill DM, Stappenbeck TS |display-authors=3|title=Debaryomyces is enriched in Crohn's disease intestinal tissue and impairs healing in mice |journal=Science |volume=371 |issue=6534 |pages=1154–1159 |date=March 2021 |pmid=33707263 |doi=10.1126/science.abd0919 |bibcode=2021Sci...371.1154J |s2cid=232199817 |url=|pmc=10114606 }}</ref> Certain strains of ''Debaryomyces hansenii'' have been researched for potential use as probiotics and may have health benefits.<ref name="pmid27430508">{{cite journal |vauthors=Ochangco HS, Gamero A, Smith IM, Christensen JE, Jespersen L, Arneborg N |display-authors=3|title=In vitro investigation of Debaryomyces hansenii strains for potential probiotic properties |journal=World Journal of Microbiology & Biotechnology |volume=32 |issue=9 |article-number=141 |date=September 2016 |pmid=27430508 |doi=10.1007/s11274-016-2109-1}}</ref><ref name="pmid26828815">{{cite journal |vauthors=Banjara N, Nickerson KW, Suhr MJ, Hallen-Adams HE |title=Killer toxin from several food-derived Debaryomyces hansenii strains effective against pathogenic Candida yeasts |journal=International Journal of Food Microbiology |volume=222 |issue=2 |pages=23–9 |date=April 2016 |pmid=26828815 |doi=10.1016/j.ijfoodmicro.2016.01.016 |doi-access=free|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1008&context=bioscinickerson }}</ref>
==Ecology== ''Debaryomyces hansenii'' is an osmo-, halo- and xerotolerant yeast<ref name=Yeast>{{cite journal | vauthors = Breuer U, Harms H | title = Debaryomyces hansenii--an extremophilic yeast with biotechnological potential | journal = Yeast | volume = 23 | issue = 6 | pages = 415–437 | date = April 2006 | pmid = 16652409 | doi = 10.1002/yea.1374 | s2cid = 26399411 | doi-access = free }}</ref> that produces toxins, including mycocins, to destroy competitive yeast species.<ref name="pmid26828815"/> It is a common species in all types of cheese, including soft cheeses and the brines of semi-hard and hard cheeses,<ref>{{cite journal | vauthors = Fleet GH | title = Yeasts in dairy products | journal = The Journal of Applied Bacteriology | volume = 68 | issue = 3 | pages = 199–211 | date = March 1990 | pmid = 2187843 | doi = 10.1111/j.1365-2672.1990.tb02566.x | doi-access = free }}</ref> and the most common yeast among 383 isolates from samples of unsulfited or sulfited sausages, skinless sausages and minced beef.<ref>{{cite journal | vauthors = Dalton HK, Board RG, Davenport RR | title = The yeasts of British fresh sausage and minced beef | journal = Antonie van Leeuwenhoek | volume = 50 | issue = 3 | pages = 227–248 | year = 1984 | pmid = 6486769 | doi = 10.1007/BF02342134 | s2cid = 20503633 }}</ref> It contributes to the fermentation of barrel-aged beers such as Le Coq Imperial Stout from Harveys Brewery 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.<ref>{{citation | url=http://www.beerhunter.com/documents/19133-001504.html | title=Washington hosts historic tasting of British and Irish classics | vauthors = Jackson M |author-link=Michael Jackson (writer) | date=6 April 2001}}</ref> ''D. hansenii'' is also found in hyper-saline waters such as the salterns on the Atlantic coast of Namibia or in the Great Salt Lake of Utah.<ref name=Yeast />
==Nutritional requirements== The species can be cultivated in media with up to 25% NaCl or 18% glycerol.<ref name=Yeast /> Growth rate increases in solutions with ≥ 1M 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 tolerance reported to date, which might have consequences for the microbial habitability of Mars, where perchlorate salts are widely distributed.<ref>{{cite journal | vauthors = Heinz J, Krahn T, Schulze-Makuch D | title = A New Record for Microbial Perchlorate Tolerance: Fungal Growth in NaClO<sub>4</sub> Brines and its Implications for Putative Life on Mars | journal = Life | volume = 10 | issue = 5 | pages = 53 | date = April 2020 | pmid = 32353964 | pmc = 7281446 | doi = 10.3390/life10050053 | bibcode = 2020Life...10...53H | doi-access = free }}</ref>
==Reproduction== Most strains are haploid, mating very rarely and diploidize transiently by somatogamous autogamy (i.e. fusion of two cells but excluding their nuclei). Sexual reproduction proceeds via heterogamous conjugation (i.e. the conjugation of two cells of different form or size) leading to short diplophase followed by meiosis and ascospore formation.<ref name=Yeast /> Haploid yeasts reproduce vegetatively 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.<ref>{{Cite web|title=Debaryomyces hansenii (ID 195) - Genome - NCBI|url=https://www.ncbi.nlm.nih.gov/datasets/genome/?taxon=4959|access-date=2020-12-31|website=www.ncbi.nlm.nih.gov}}</ref>
==Differentiation== The ability of this species to grow at 10% NaCl or 5% glucose is used to discriminate ''D. hansenii'' from other ascomycetous yeasts.<ref name=Yeast /> The species comprises two varieties: ''D. hansenii'' var. ''hansenii'' and var. ''fabryii''. These two groups can be differentiated via rRNA, the electrophoretic mobility of their glucose-6-phosphate dehydrogenase, 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, riboflavin, xylitol, and pyruvic acid under thiamine limitation.<ref name=Yeast /> The species has also been used to decarboxylate ferulic acid to 2-Methoxy-4-vinylphenol via biotransformation (a 95.07% yield, 1470.8 mg/L, within 10 hours).<ref>{{cite journal| vauthors = Mathew S, Abraham TE, Sudheesh S |title=Rapid conversion of ferulic acid to 4-vinyl guaiacol and vanillin metabolites by ''Debaryomyces hansenii''|journal=Journal of Molecular Catalysis B: Enzymatic|date=2007|volume=44|issue=2|pages=48–52|doi=10.1016/j.molcatb.2006.09.001}}</ref>
== References == {{Reflist}}
== External links == *{{IndexFungorum|296478}}
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Category:Food microbiology Category:Fungi described in 1889 Category:Yeasts Category:Osmophiles Category:Halophiles Category:Xerophiles Category:Pichiomycetes Category:Taxa named by Friedrich Wilhelm Zopf Category:Fungus species