Killer yeasts secrete polypeptide toxins which kill sensitive cells of their own
species and frequently those of other species and genera of yeasts. These protein compounds are designated as killer toxins. Also killer toxins of certain yeast strains have potential growth inhibitory activity on gram-positive pathogenic bacteria and plant pathogenic fungi. The yeasts are immune to their own killer protein. The killer phenomenon can be utilized for the protection of fermentation process against contaminating yeasts and for biological control of undesirable yeasts in the preservation of foods. The killer trait can also be used to produce large amount of foreign proteins in yeast. In the medical field , it is thought that their anti-microbial and anti-mycotic activity could be exploited in a therapeutic strategy.
Yeast killer toxins are classified into 11 types according to their killing
spectra and immunity-specificities such as K1, K2, etc. Altough there is
considerable amount of published information concerning the applications of yeast killer toxins , among the 11 types , only K1 , K2 and K6 have been characterized. In this study , it was aimed to purify and characterize the K4 type yeast killer toxin secreted by the Hansenula anomala NCYC 432. Gel permeation chromatography was performed to isolate the killer toxin by using a HPLC system. The toxin was
shown to be a glycoprotein having a molecular mass of between 49.08 kDa and 47.25 kDa and isoelectric point of between 3.77 and 3.41.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/1218684/index.pdf |
| Date | 01 January 2003 |
| Creators | Acun, Tolga |
| Contributors | Izgu, Fatih |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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