Yarrowia

Yarrowia is a fungal genus in the family Dipodascaceae. For a while the genus was monotypic, containing the single species Yarrowia lipolytica, a yeast that can use unusual carbon sources, such as hydrocarbons.[2] This has made it of interest for use in industrial microbiology, especially for the production of specialty lipids.[3] Molecular phylogenetics analysis has revealed several other species that have since been added to the genus.[4][5][6]

Yarrowia
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Saccharomycetes
Order:	Saccharomycetales
Family:	Dipodascaceae
Genus:	Yarrowia Van der Walt & Arx (1981)[1]
Type species
Yarrowia lipolytica (Wick., Kurtzman & Herman) Van der Walt & Arx (1980)
Species
Yarrowia bubula Yarrowia deformans Yarrowia lipolytica Yarrowia porcina Yarrowia yakushimensis Yarrowia parophonii

In January 2019, Yarrowia lipolytica yeast biomass was defined by the European Food Safety Authority as a safe novel food – dried and heat‐killed – with the underlying qualifications that it is widespread in nature, present in the typical environment, may be used as food for people over age 3 (3 grams per day for children under age 10, and 6 grams per day for teens and adults), and may be manufactured as a dietary supplement.[7]

Biology

Habitat

Y. lipolytica has been isolated from various locations (e.g. milled corn fiber tailings, or Paris sewer [8]). Often these environments contain an excess of lipids, which can be efficiently utilized by Y. lipolytica as a carbon and energy source [9]. Y. lipolytica is strictly aerobic [10].

Oleaginous yeast

Singe cell state of Yarrowia lipolytica under microscope.

Y. lipolytica is part of the group of oleaginous yeast, which means that its cells are made up of more then 20% fat content [10]. Most lipids are stored as triacylglycerids (TAGs). This physiological trait makes this species especially interesting to produce lipid derivates. For example, genetic engineering and process optimization allow to produce high amounts of eicosapentaenoic acid (EPA) [11].

Dimorphism

Filamentous cell state of Yarrowia lipolytica

Y. lipolytica has a dimorphic growth [10], which means it can grow in two different phenotypes. The usual form of the cells can be described as round and spherical. When exposed to stress conditions such as temperature, pH, mechanical or osmotic stress,[12] the cell can switch into a filamentous growth form (also see hyphae).

Genome

The genome of Y. lipolytica consists of around 20,5 kbp (kilo base pairs), encodes for over 7000 genes and is distributed on six chromosomes (named A to F) and the mitochondrial DNA (M). Naturally, there are small differences in the length of the genomes of different strain isolates. Usually hemiascomycetous yeast have a low number of introns, however, Y. lipolytica is an exception with about 15% of genes containing introns. [13]

References

1. van der Walt JP, von Arx JA (1980). "The yeast genus Yarrowia gen. nov". Antonie van Leeuwenhoek. 46 (6): 517–21. doi:10.1007/bf00394008. PMID 7195185.
2. Flores CL, Gancedo C (February 2005). "Yarrowia lipolytica mutants devoid of pyruvate carboxylase activity show an unusual growth phenotype". Eukaryotic Cell. 4 (2): 356–64. CiteSeerX 10.1.1.318.2901. doi:10.1128/EC.4.2.356-364.2005. PMC 549329. PMID 15701798.
3. Papanikolaou S, Aggelis G (2010). "Yarrowia lipolytica: A model microorganism used for the production of tailor-made lipids". European Journal of Lipid Science and Technology. 112 (6): 639–654. doi:10.1002/ejlt.200900197.
4. Michely S, Gaillardin C, Nicaud JM, Neuvéglise C (2013). "Comparative physiology of oleaginous species from the Yarrowia clade". PLOS ONE. 8 (5): e63356. Bibcode:2013PLoSO...863356M. doi:10.1371/journal.pone.0063356. PMC 3646758. PMID 23667605.
5. Nagy E, Dlauchy D, Medeiros AO, Péter G, Rosa CA (April 2014). "Yarrowia porcina sp. nov. and Yarrowia bubula f.a. sp. nov., two yeast species from meat and river sediment". Antonie van Leeuwenhoek. 105 (4): 697–707. doi:10.1007/s10482-014-0125-4. PMID 24500004. S2CID 14196562.
6. Crous PW, Wingfield MJ, Burgess TI, Carnegie AJ, Hardy GE, Smith D, et al. (December 2017). "Fungal Planet description sheets: 625-715". Persoonia. 39: 270–467. doi:10.3767/persoonia.2017.39.11. PMC 5832955. PMID 29503478.
7. EFSA Panel on Nutrition, Novel Foods and Food Allergens (14 February 2019). "Safety of Yarrowia lipolytica yeast biomass as a novel food pursuant to Regulation (EU) 2015/2283". EFSA Journal. European Food Safety Authority. 17 (2): e05594. doi:10.2903/j.efsa.2019.5594.
8. Wolf, Klaus (1996). "Nonconventional Yeasts in Biotechnology". doi:10.1007/978-3-642-79856-6. Cite journal requires |journal= (help)
9. Kurtzman, Cletus P. (2011-01-01), Kurtzman, Cletus P.; Fell, Jack W.; Boekhout, Teun (eds.), "Chapter 82 - Yarrowia van der Walt & von Arx (1980)", The Yeasts (Fifth Edition), London: Elsevier, pp. 927–929, ISBN 978-0-444-52149-1, retrieved 2020-06-24
10. Nicaud JM (October 2012). "Yarrowia lipolytica". Yeast. 29 (10): 409–18. doi:10.1002/yea.2921. PMID 23038056.
11. Xie D, Jackson EN, Zhu Q (February 2015). "Sustainable source of omega-3 eicosapentaenoic acid from metabolically engineered Yarrowia lipolytica: from fundamental research to commercial production". Applied Microbiology and Biotechnology. 99 (4): 1599–610. doi:10.1007/s00253-014-6318-y. PMC 4322222. PMID 25567511.
12. Ruiz-Herrera J, Sentandreu R (December 2002). "Different effectors of dimorphism in Yarrowia lipolytica". Archives of Microbiology. 178 (6): 477–83. doi:10.1007/s00203-002-0478-3. PMID 12420169. S2CID 22869104.
13. Mekouar, Meryem; Blanc-Lenfle, Isabelle; Ozanne, Christophe; Da Silva, Corinne; Cruaud, Corinne; Wincker, Patrick; Gaillardin, Claude; Neuvéglise, Cécile (2010-06-23). "Detection and analysis of alternative splicing in Yarrowia lipolytica reveal structural constraints facilitating nonsense-mediated decay of intron-retaining transcripts". Genome Biology. 11 (6): R65. doi:10.1186/gb-2010-11-6-r65. ISSN 1474-760X.