Nally M C, Maturano Y P, Vázquez F, Toro M E
Instituto de Biotecnología, Facultad de Ingeniería, Universidad Nacional de San Juan, Avda. Libertador General San Martin 1109 (Oeste) (5400), San Juan.
Rev Argent Microbiol. 2005 Apr-Jun;37(2):73-7.
Wine chemical composition is the outcome of complex chemosensory interactions that are difficult to predict because of the influences of many variables, like as yeast-yeast interactions. Killer phenomenon implicates the secretion of a toxic protein by some yeasts, that kill other yeasts called sensitive. The knowledge of the behaviour of killer-sensitive mixed cultures in aerobic conditions is useful to be related with the first stages of oenological fermentation. In these stages it can be defined the killer prevalence in the medium. Also, the use of cured plasmid mutants allows better comparisons. The objective was to analyse the mechanism of substrate competition in Saccharomyces cerevisiae killer strains and its sensitive cured plasmid mutant, using different nitrogen sources. When samples were incubated at the toxin inactivation temperature, the infraestimation of sensitive cells is avoided. Results obtained in co-cultures (50%K-50%S) show the role of the nitrogen source in killer activity. Results obtained with 10%K-90%S inoculum, show that there are another competence variables than the competitive exclusion model for killer yeasts.
葡萄酒的化学成分是复杂化学感官相互作用的结果，由于许多变量的影响，如酵母与酵母之间的相互作用，这些相互作用难以预测。杀手现象涉及一些酵母分泌一种有毒蛋白质，这种蛋白质会杀死其他被称为敏感型的酵母。了解有氧条件下杀手-敏感混合培养物的行为，有助于与酿酒发酵的初始阶段相关联。在这些阶段，可以确定培养基中杀手型酵母的占比。此外，使用治愈质粒突变体可以进行更好的比较。目的是分析酿酒酵母杀手菌株及其敏感治愈质粒突变体在使用不同氮源时的底物竞争机制。当样品在毒素失活温度下孵育时，可以避免对敏感细胞的低估。共培养（50%杀手型-50%敏感型）获得的结果表明了氮源在杀手活性中的作用。用10%杀手型-90%敏感型接种物获得的结果表明，对于杀手型酵母，除了竞争排斥模型外，还有其他竞争变量。
