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Scientists have used genetic modification to create ''S. cerevisiae'' strains that produce various killer toxins that can assist in completing fermentation in the baking, wine, distillation, and beer making processes. These yeasts are able to inhibit undesired yeast contaminants, preventing various off-flavors and other unwanted characteristics in the finished products. Ale and lager strains that have been modified to release these toxins have reportedly retained the positive fermentation and flavor characteristics of the original strains <ref name="Bajaj_2017" />.
Several strains of ''Saccharomyces eubayanus'' isolated from seeds from monkey puzzle trees in Patagonia, Argentina, were found to secrete a killer toxin that kills ''Brettanomyces'' and ''Pichia''. One strain was found to produce a lot of the toxin, which is called "SeKT". The researchers found that SeKT toxin produced by this one strain of ''S. eubaynus'' in a special growth medium designed to maximize the SeKT toxin production inhibited a strain of ''B. bruxellensis'' to around 50% growth after 48 hours in a wine growth medium. It also inhibited ''Pichia guilliermondii'', ''Pichia manshurica'', and ''Pichia membranifaciens'' by 50-70%. The toxin has thus been proposed as a way to limit ''Brettanomyces'' and ''Pichia'' in wine fermentations <ref>[https://www.ncbi.nlm.nih.gov/pubmed/30671692?dopt=Abstract Production of a novel killer toxin from Saccharomyces eubayanus using agro-industrial waste and its application against wine spoilage yeasts. Mazzucco MB, Ganga MA, Sangorrín MP. 2019. DOI: 10.1007/s10482-019-01231-5.]</ref>.
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2202753476419521/?comment_id=2202936416401227&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Bryan Heit's simple method for testing for killer sensitivity using nothing more than agar plates.]