Debaryomyces hansenii

Debaryomyces hansenii is a species of yeast in the family Saccharomycetaceae. Also known as Candida famata, it accounts for up to 2% of invasive candidiasis cases.[1]

Debaryomyces hansenii
Scientific classification
Kingdom:
Fungi
Division:
Ascomycota
Class:
Saccharomycetes
Order:
Saccharomycetales
Family:
Saccharomycetaceae
Genus:
Debaryomyces
Species:
D. hansenii
Binomial name
Debaryomyces hansenii
(Zopf) Lodder & Kreger-van Rij (1984)
Synonyms
  • Saccharomyces hansenii Zopf (1889)

Ecology

Debaryomyces hansenii is an osmo-, halo- and xerotolerant yeast[2] that produces toxins, including mycocins, to destroy competitive yeast species.[3] It is a common species in all types of cheese, including soft cheeses and the brines of semi-hard and hard cheeses,[4] and the most common yeast among 383 isolates from samples of unsulphited or sulphited sausages, skinless sausages and minced beef.[5] 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.[6] 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.[2]

Nutritional requirements

The species can be cultivated in media with up to 25% NaCl or 18% glycerol.[2] 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.

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.[2] 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.[7]

Differentiation

The ability of this species to grow at 10% NaCl or 5% glucose is used to discriminate D. hansenii from other ascomycetous yeasts.[2] 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.[2] 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).[8]

References
  1. Garey, Kevin W.; McCaskey, Laurie; Ng, Tat Ming; Shah, Dhara N.; Alam, M. Jahangir; Chuang, Shen Hui; Beyda, Nicholas D. (2013-02-01). "Treatment of Candida famata bloodstream infections: case series and review of the literature". Journal of Antimicrobial Chemotherapy. 68 (2): 438–443. doi:10.1093/jac/dks388. ISSN 0305-7453. PMID 23085777.
  2. Uta Breuer; Hauke Harms (2006). "Debaryomyces hansenii — an extremophilic yeast with biotechnological potential". Yeast. 23 (6): 415–437. doi:10.1002/yea.1374. PMID 16652409.
  3. Nabaraj Banjaraa; Kenneth W. Nickersonb; Mallory J. Suhra; Heather E. Hallen-Adamsa (2016). "Killer toxin from several food-derived Debaryomyces hansenii strains effective against pathogenic Candida yeasts". International Journal of Food Microbiology. 222 (2): 23–29. doi:10.1016/j.ijfoodmicro.2016.01.016. PMID 26828815.
  4. Fleet, G.H. (1990). "Yeasts in dairy products". Journal of Applied Bacteriology. 68 (3): 199–211. doi:10.1111/j.1365-2672.1990.tb02566.x. PMID 2187843.
  5. Hilary K. Dalton; R. G. Board; R. R. Davenport (1984). "The yeasts of British fresh sausage and minced beef". Antonie van Leeuwenhoek. 50 (3): 227–248. doi:10.1007/BF02342134. PMID 6486769. S2CID 20503633.
  6. Jackson, Michael (6 April 2001), Washington hosts historic tasting of British and Irish classics
  7. "Debaryomyces hansenii (ID 195) - Genome - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2020-12-31.
  8. Sindhu Mathewa; Emilia Abrahama; S. Sudheesh (2007). "Rapid conversion of ferulic acid to 4-vinyl guaiacol and vanillin metabolites by Debaryomyces hansenii". Journal of Molecular Catalysis B: Enzymatic. 44 (2): 48–52. doi:10.1016/j.molcatb.2006.09.001.
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