Kitamoto H K, Hasebe A, Ohmomo S, Suto E G, Muraki M, Iimura Y
National Institute of Agrobiological Resources, Tsukuba, Ibaraki 305-8602, Japan.
Appl Environ Microbiol. 1999 Oct;65(10):4697-700. doi: 10.1128/AEM.65.10.4697-4700.1999.
In this study, we propose a new process of adding a genetically modified killer yeast to improve the aerobic stability of silage. Previously constructed Kluyveromyces lactis killer strain PCK27, defective in growth on lactic acid due to disruption of the gene coding for phosphoenolpyruvate carboxykinase, a key enzyme for gluconeogenesis, inhibited the growth of Pichia anomala inoculated as an aerobic spoilage yeast and prevented a rise in pH in a model of silage fermentation. This suppressive effect of PCK27 was not only due to growth competition but also due to the killer protein produced. From these results, we concluded that strain PCK27 can be used as an additive to prolong the aerobic stability of maize silage. In the laboratory-scale experiment of maize silage, the addition of a killer yeast changed the yeast flora and significantly reduced aerobic spoilage.
在本研究中，我们提出了一种添加转基因嗜杀酵母以提高青贮饲料有氧稳定性的新方法。先前构建的乳酸克鲁维酵母嗜杀菌株PCK27，由于编码磷酸烯醇式丙酮酸羧激酶（糖异生关键酶）的基因被破坏，在乳酸上生长存在缺陷，它抑制了作为好氧性变质酵母接种的异常毕赤酵母的生长，并在青贮饲料发酵模型中阻止了pH值升高。PCK27的这种抑制作用不仅归因于生长竞争，还归因于所产生的嗜杀蛋白。基于这些结果，我们得出结论，菌株PCK27可用作添加剂来延长玉米青贮饲料的有氧稳定性。在玉米青贮饲料的实验室规模实验中，添加嗜杀酵母改变了酵母菌群并显著减少了好氧性变质。
