Pichia kudriavzevii: Difference between revisions

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==Genome Structure==
==Genome Structure==


''P. kudriavzevii'' has average eukaryotic chromosome structure and DNA. In summary, as the organism undergoes meiosis, two pairs of chromosomes recombine and separate. The chromosome is found to be 3 to 8 bands in length (Chan). The linear DNA is found in the nucleus, with a standard code. On average, the nuclear DNA 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 is circular with approximately  51 thousand base pairs (Hong). Since there are very few full genome sequences (8 total), not much is know about the ''P. kudriaveii'' genome (www.ncbi.nlm.nih.gov).
''P. kudriavzevii'' has average eukaryotic chromosome structure and DNA. In summary, as the organism undergoes meiosis, two pairs of chromosomes recombine and separate. The chromosome is found to be 3 to 8 bands in length (Chan). The linear DNA is found in the nucleus, with a standard code. In other words, AUG is used as the start codon and UAA/UGA/UAG are used as the stop codons. On average, the nuclear DNA 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 is circular with approximately  51 thousand base pairs (Hong). Since there are very few full genome sequences (8 total), not much is know about the ''P. kudriaveii'' genome (www.ncbi.nlm.nih.gov).


[[File:xylose_2.png|thumb|Fermentation of Xylose]]
[[File:xylose_2.png|thumb|Fermentation of Xylose]]

Revision as of 20:54, 16 April 2018

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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 the sexual reproduction stage of an organisms; thus, Pichia kudriavzevii reproduces sexually. The asexual state of a fungi is called an "anamorph" (Guarri et al). The yeast was first named Issatchenkia orientalis by V.I. Kudryavtsev in 1960 and was changed to Pichia 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. Pichia kudriavzeii can remain metabolically active in temperatures as high as 45°C and in pHs as low as 2 (Greppi and Oberoi). It produces ethanol at a high yield, which is very useful for the biofuel industry (Oberori). 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 for cocoa beans. It can be a pathogen under some circumstances and yet there are only a few pathogenic cases documented because Pichia kudriazveii is only documented to infect those with an immunodeficiency (Hurst).

Genome Structure

P. kudriavzevii has average eukaryotic chromosome structure and DNA. In summary, as the organism undergoes meiosis, two pairs of chromosomes recombine and separate. The chromosome is found to be 3 to 8 bands in length (Chan). The linear DNA is found in the nucleus, with a standard code. In other words, AUG is used as the start codon and UAA/UGA/UAG are used as the stop codons. On average, the nuclear DNA 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 is circular with approximately 51 thousand base pairs (Hong). Since there are very few full genome sequences (8 total), not much is know about the P. kudriaveii genome (www.ncbi.nlm.nih.gov).

Fermentation of Xylose

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.

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