# The Biology of _Pichia membranifaciens_ Killer Toxins
## 6 Applications, Conclusions and Future Perspectives of _P. membranarificiens_ Killer Toxins
membranarificiens_ has also been used as a biological tool for the control of other crop-fruit-associated fungus pathogens such as _Penicillium expansum_ in postharvest peaches (by rapid colonization and competition for space and nutrients in fruit wounds) [163] and in postharvest peers (by nutrient and space competition and the production of chitinase, glucanase and other killer activities) [155]; _Colletotrichum acutatum_ causing anthracose rot in postharvest loquat fruit (by producing chitinase and \(\beta\)-1,3-glucanase) [164]; _Penicillium roqueforti_ in storage wheat grain (with no conclusions about the mechanism of action) [160]; and _Penicillium italicum_, _Penicillium digitatum_ and _Colletotrichum gloeosporoides_ causing blue and green mold and anthracose in citrus fruit (with no conclusions about the mechanism of action) [165]. \begin{table}
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**Applications** & **Organism/s** & **Toxin** & **General Description** & **References** \\ \hline
**Biological models** & _Satchnumbers cerevisiae_ & K28 & Model for the study of proteins, lipids, and mechanisms required on endocytosis and retrograde trafficking in A/B toxins (Ricin, Shiga, and Choleza toxins) & [166] \\ \hline \multirow{5}{*}{**Bioplying**} & Killer strains panel & - & Fingerprinting and clustering yeast strains (gorenz _Dubernyers, Klaprownyos,_ _Satchnumbers, and ZygosiChromos) by use of killer toxin sensitive patterns & [167] \\ \cline{2-5}  & _Satchnumbers cerevisiae_ & - & Typing \(S\)_. cerevisiae_ strain by combined use of RAPD and killer toxin sensitivity patterns & [168] \\ \cline{2-5}  & _Cryoprotoc  
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**Applications** & **Organism/A** & **Toxin** & **General Description** & **References** \\ \hline \multirow{8}{*}{**Prevention of** **demonstrations in** **demonstration** **industries**} & _Soccharomyces cerevisiae_ & - & Effect of Miller strains of \(S\). cerevisiae on the growth of sensitive strains during wine fermentation, to improve the selected wine strain implantation. Sparaking wines quality improvement & [180, 181] \\ \cline{2-4}  & _Kliosevomyces phuffii_ (DWPC 6076) & - & Use of \(K\). phuffii killer fusion to control particulate spoilage wine yeast (_Hessvossian serum_) & [182] \\ \cline{2-4}  & _Traniaguru dehrbrachti_ (NPTC 1033) & TdxRT & Application of a novel killer fusion (TdxRT) from \(T\). Edward is a biocontrol tool in winemaking against different wine spoilage yeasts & [9] \\ \cline{2-4}  & _Utaliago mavdis_ (CYC 1410) & - & Use of \(U\). mavdis points for the location of _Hennymos traciliensis_ for the reduction of aroma defects caused by this spoilage yeast & [10] \\ \cline{2-4}  & _Candidia readensis_ (PYCC 3198) & CnRT & Application of CnRT in the preservation of salt-permemed foods, because of its high stability to salinity & [45] \\ \cline{2-4}  & _D. hansocrit, K. muzzins, P. annutial, F. gullermermoult, S. cerevisiae_ & - & Control of olive table fermentation by the selection of killer yeast and their & [86] \\ \cline{2-4}  & _[PERSON]  
The activity of _P. membranitaciens_ towards the wine spoilage yeast _B. bruxellensis_ was firstly observed by [PERSON] et al. (2000) [189], and this fact was later confirmed by [PERSON] et al. (2009), who verified the inhibition of _P. membranitaciens_ CYC 1086 and its killer toxin PMKT2 against _B. bruxellensis_ in simulated winemaking conditions [20]. Apart from the use of _P. membranitaciens_ CYC 1086 and PMKT2, killer toxins from _Ustilago maydis_[10], _Torulaspora delbrueckii_ (TdKT) [9], _Kluyveromyces wickerhamii_ (Kwkt), _Wickerhamomyces anomalus_ (Pikt) [183] and _Candida pyralidae_ (CpKT1) [184] and the production of pulcherriminic acid by _Metschnikowia pulcherrima_ (without a real killer activity but depleting biologically available iron from the medium) [190] have been reported as useful to control _Brettanomyces_ spoilage. Continuing in the enology context, results from [PERSON] et al.