''Kazachstania yasuniensis'' is a recently isolated

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

. This organism is part of the genus '' Kazachstania'', which can be found in a large variety of habitats such as

fermented food In food processing, fermentation is the conversion of carbohydrates to alcohol or organic acids using microorganisms—yeasts or bacteria—under anaerobic (oxygen-free) conditions. Fermentation usually implies that the action of microorgani ...

s, animals,

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial ...

, et cetera.

Isolation

''Kazachstania yasuniensis'' was isolated on

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ' ...

and the Galápagos archipelago in

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

regions. Seven strains of the genus ''Kazachstania'' were isolated in order to provide a thorough

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

for the novel species. These samples were cultured on 7.6% ethanol medium (Sniegowski ''et al.'' 2002). They were isolated either from rotten wood, soil, or decaying fruits. Based upon where these species were isolated, researchers concluded that ''K. yasuniensis'' most likely resides in an arboreal habitat. The strains were collected from the Ecuadorian Amazon, as well as the ''Scalesia'' forest of

Santa Cruz Island Santa Cruz Island ( Spanish: ''Isla Santa Cruz'', Chumash: ''Limuw'') is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the eight islands in the Channel Islands ...

in the Galápagos islands. Although no

Gram staining In microbiology and bacteriology, Gram stain (Gram staining or Gram's method), is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. The name comes from the Danish bac ...

was performed, using a scanning electron microscope, ''K. yasuniensis'' cells were found to be ovoid and either single, paired, or in short chains or groups of cells.

Characteristics

Morphologically, standard methods such as growth temperature testing using yeast extract-malt extract agar cultivation and

sporulation In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

tests on various agars were used. As far as physiological characterization goes, the novel species differed from its close relatives in that it absorbed

trehalose Trehalose (from Turkish '' tıgala'' – a sugar derived from insect cocoons + -ose) is a sugar consisting of two molecules of glucose. It is also known as mycose or tremalose. Some bacteria, fungi, plants and invertebrate animals synthesize it ...

and

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

, while growing on ethylamine

hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...

and sodium chloride. It was also unable to grow at 37 °C and absorb glucose, and could absorb sucrose, all of which are physiological aspects that differ from its close relatives. The ''Si'' value was calculated for the species as well. A higher ''Si'' value indicates a more specialized species. The value for ''K. yasuniensis'' was 0.62, and therefore characterized with the majority of yeast species found in highly specialized environments. ''Kazachstania yasuniensis'' was found to absorb and metabolize glucose, sucrose, raffinose, galactose, trehalose, cadaverine, ethylamine hydrochloride, and ethanol. It could not grow on inulin, melibiose, lactose, maltose, melezitose, methyl α- d-glucoside, starch, cellobiose, salicin, l-sorbose, l-rhamnose, d-xylose, l-arabinose, d-arabinose, d-ribose, methanol, glycerol, erythritol, ribitol, galactitol, d-mannitol, d-glucitol, inositol, dl-lactate, succinate, citrate, d-glucosamine, glucono- d-lactone, ysine, nitrate, xylitol, or 50% glucose/yeast extract. The organism proliferated at 30 °C, but there was no growth at 37 °C. Multigene sequencing needs to be performed in order to establish clearer boundaries between yeast species. This is a very novel species and there is still much to be discovered.

References

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Isolation

Characteristics

References

Further reading