Pichia kudriavzevii

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Classification

Domain: Eukaryota

Phylum: Ascomycota

Class: Saccharomycetes

Order: Saccharomycetales

Family: Pichiaceae

Genus: Pichia

[Others may be used. Use NCBI link to find]

Species

NCBI: Taxonomy

Pichia kudriavzevii

Image of Pichia kudriavzevii

Description and Significance

Pichia kudriavzevii is the teleomorph of the Candida krusei. A teleomorph is _____________ of an organisms; thus, Pichia kudriavzevii reproduces sexually. The yeast was first named Issatchenkia orientalis by V.I. Kudryavtsev in 1960 and then, was changed to P. kudriavzevii in 1965 (brewery).

The shape of cells can be oval or ellipsoidal to elongate. (Obroi, 2012) It is very abundant in the environment and can be found easily in soil, on the skins of fruits and even in fermented beverages. Like most yeast, Pichia kudriavzeii is involved in the fermentation of wine and beer. However, it is also very valuable in cocoa bean heap fermentation, creating a greater flavor and aroma of cocoa beans. It can be a pathogen under some circumstances and yet there are only a few pathogenic cases documented because Pichia kudriazveii (rarely) infects those with an immunodeficiency (Hurst). Pichia kudriavzeii takes an important role in food industry because it ferments glucose. (add part about why glucose is important in food industry)

The Pichia kudriavzeviin severs an important role in the biofuel production as it can produce ethanol with a very high yield. It can tolerate a temperature of 40 degrees, which is very high for yeast and remain its activity, so it can survive under high tension ethanol production. And it remain active at very low pH even in the environment of human stomach. It is very important to the daily life of the human beings as biofuels are becoming a more popular alternative to fossil fuels.


Describe the appearance, habitat, etc. of the organism, and why you think it is important.

Genome Structure

P. kudriavzevii has linear DNA with a standard code. On average, it contains approximately 10 million base pairs, with around 5 thousand being protein-coding genes. The GC count is around 38% with 3 of the genes coding for phytase, an enzyme that catalyzes the hydrolysis of phytic acid (Chan). The mitochrondian DNA has circular DNA with approximately 51 thousand base pairs (Hong). The chromosome is found to be 3 to 8 bands in length (Chan). Since there are very few genome sequences (8 total), not much is know about the P. kudriaveii genome(www.ncbi.nlm.nih.gov).

Cell Structure, Metabolism and Life Cycle

Like many other yeast cells, the Pichia kudriavzevii cell is constructed with cytoplasm, nucleus, cell membrane, chitin cell wall, mitochondrion and vacuole. It can use glucose, sucrose, galactose, fructose, and mannose as food resources. Pichia kurivazveii is very good at hydrolyzing phytate with phytase, which is very unique. Plants can use hydrolyzed phytate as phosphorus recourse so plants and Pichia kudriazveii can reach a relationship of symbiont. Although lots of yeast have the ability of producing ethanol, there is not much yeasts can produce bioethanol with Xylose which is sugar found in the wood. It means it can use wood to produce ethanol which is very essential for the biofuel industry. Pichia kudriavzveii can reproduce through bisexual interaction after meiosis. The life cycle of Pichia kudriavzevii in wine is remained undiscovered for now.

Interesting features of cell structure; how it gains energy; what important molecules it produces.

Image of Pichia kudriavzevii

Ecology and Pathogenesis

P. kudriavzevii can be found in soil and on the outside of fruits and vegetables, often in the presence of other Pichia species. Although it is found on the outside of produce, it is not considered a species that is responsible for food spoilage (Kurtzman). Instead, P. kudriavzeii can be helpful when developing an environementally-friendly food preservative (Bajaj et. al). It can also be isolated from many different fermentations ranging from fruit juice to cocoa bean heap and it is particularly useful in amplifying the aroma of chocolate (Obeori et. al).

Since this organism contains 3 genes that code for phytases, there is a symbiotic relationship between P. kudriavzevii and plants. For instance, the phytases present in the yeast degrade phytate present in soil, improving the amount of phosphate intake from the plants. As a result, there is a reduction in the amount of phosphorus fertilizer needed (Chan et. al).

P. kudriazvevii can be used in wine fermentation without becoming pathogenic, therefore, some would consider P. kudriavzevii to be a "opportunistic pathogen." It can lead to mastitis (infection of the breast tissue) in mammals, but this type of disease is most commonly found in dogs and cattle (Hurst). There are few cases of humans being severely impacted by the presence of P. kudriazvevii; however, there was an outbreak of sepsis due to P. kudriazvevii in a neonatal intensive care unit in 2017. This was the first documented case of neonatal sepsis due to P. kudrizvevii. On the other hand, the anamorph of P. kudrizvevii (Candida species) is one of the most common causes of late on-set fungal sepsis, so it can be inferred that more cases of P. kudrivzevii-induced sepsis will start to appear (Nagarathnamma et. al). Some general symptoms of sepsis include fever, hypothermia, fast heart rate, swelling, and high blood glucose levels. Some symptoms specific to sepsis are (but are not limited to) a high white blood cell count, low oxygen level, low urine output, high lactate in blood, and a decrease in capillary filling (Sepsis.org)

References