Cryptococcus antarcticus

Cryptococcus antarcticus is a species of Cryptococcus that has been isolated from soil in Antarctica, as the name suggests. This species grows best between 4 °C (39 °F) and 20 °C (68 °F), and some strains of C. antarcticus have been observed to grow upwards of 25 °C (77 °F). This temperature range is one of the only things that can distinguish it from C. albidus var. albidus on the DNA level, however, it can be phenotypically differentiated through its ability to utilize different minerals and its overall appearance. When plated the colonies have a slightly mucosoid appearance, with a white to cream coloration. C. antarcticus is able to assimilate nitrogen and glucoronate, and some strains can turn a dirty yellow when assimilating the previously mentioned compounds. When being cultured in liquid media, constant agitation is required. On a microscopic level this yeast is ovoid in shape. C. antarcticus has not been seen to sexually reproduce, but when they do reproduce asexually they do so through budding. Mature cells that have not recently budded typically are 4.0 μm by 7.5 μm, and they do not appear to produce pseudomycelium. C. antarcticus is not able to ferment, but all of its strains use cellobiose, 2-ketogluconate in hemicalcium salt, gluconate at pH 5.8, glucuronate at pH 5.5, maltose, mannitol, melezitose, soluble starch and succinate at pH 5.5 as sole carbon sources. Only certain strains of C. anarcticus can use citrate at pH 6.0, D-glucitol, L-arabinose, raffinose and xylose as sole carbone sources. This species does not require vitamins for optimal growth. Cryptococcus anarcticus is able to produce amylose. This species is also able to assimilate L-lysine, nitrate and cadaverine as nitrogen sources.