Changes

Various other yeast species have the ability to produce toxins that effect a range of other yeasts and bacteria, including species from the genera ''Candida'', ''Cryptococcus'', ''Debaryomyces'', ''Hanseniaspora'', ''Hansenula'', ''Kluyveromyces'', ''Metschnikowia'', ''Pichia'', ''Ustilago'', ''Torulopsis'', ''Williopsis'', ''Zygosaccharomyces'', ''Aureobasidium'', ''Zygowilliopsis'', and ''Mrakia'' <ref name="Buyuksirit">[http://waset.org/publications/9999528/antimicrobial-agents-produced-by-yeasts Antimicrobial Agents Produced by Yeasts. T. Buyuksirit, H. Kuleasan. 2014.]</ref><ref name="Stewart_2018" />. For example, strains of the yeast species ''Candida pyralidae'' <ref name="Buyuksirit"></ref>, ''Wickerhamomyces anomalus'', ''Kluyveromyces wickeramii'', ''Torulaspora delbrueckii'' and ''Pichia membranifaciens'' have been found to produce toxin that inhibits ''Brettanomyces'' <ref name="Ciani_2016">[https://www.researchgate.net/publication/301581233_Yeast_Interactions_in_Inoculated_Wine_Fermentation Yeast Interactions in Inoculated Wine Fermentation. Maurizio Ciani, Angela Capece, Francesca Comitini, Laura Canonico, Gabriella Siesto and Patrizia Romano. 2016.]</ref>. In addition, the toxin produced by ''Wickerhamomyces anomalus'' and ''Williopsis markii'' have been found to inhibit a wide range of spoilage and pathogenic fungi <ref name="Hatoum2012"></ref>. Killer strains of ''S. cerevisiae'' and other yeast can occur naturally in the wild on fruit and can have a negative impact on other flora that are found in the same environment <ref name="Buyuksirit"></ref>. Strains of ''Torulaspora delbrueckii'' have been shown to kill killer strains of ''S. cerevisae'' (wine strains), as well as to kill ''Pichia'' species <ref name="Ciani_2016"></ref>.

* [https://www.homebrewtalk.com//forum/threads/from-the-lab-wine-yeast-pof-and-killer-status.648095/ List of killer strains as well as phenol production (4VG and 4VP) in various wine yeasts, compiled from a scientific study Hisamoto et al. (2010).]

* For the implications of this on re-yeasting beer with wine yeast at packaging, see the [[Packaging#Re-yeasting|Packaging]] page.