Protease-secreting yeasts have broad biotechnological potential for application to various industrial processes, including winemaking. However, this activity is influenced by the yeast response to environmental factors such as nitrogen and protein sources, as are found in grape juice. In this study, the wine-relevant yeast Metschnikowia pulcherrima IWBT Y1123, with known protease-secreting ability, was subjected to different nitrogen-containing compounds to monitor their impact on protease secretion and activity. Protease activity increased above basal levels for haemoglobin-containing treatments, indicating an inductive influence of proteins. On the other hand, treatments containing both haemoglobin and assimilable nitrogen sources led to a delayed increase in protease activity and protein degradation, suggesting a nitrogen catabolite repression mechanism at work. Protease activity and expression were furthermore evaluated in grape juice, which revealed increased expression and activity levels over time as promising results for further investigations into the impact of this yeast on wine properties.

中文翻译：

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天冬氨酸蛋白酶MpAPr1在大叶梅花IWBT Y1123中的表达，分泌和活性。

分泌蛋白酶的酵母具有广泛的生物技术潜力，可应用于包括酿酒在内的各种工业过程。然而，这种活性受酵母对葡萄汁中诸如氮和蛋白质源等环境因素的反应的影响。在这项研究中，与葡萄酒相关的酵母Metschnikowia pulcherrima IWBT Y1123，具有已知的蛋白酶分泌能力，被置于不同的含氮化合物中，以监测其对蛋白酶分泌和活性的影响。对于含血红蛋白的治疗，蛋白酶活性增加到基础水平以上，表明蛋白质具有诱导作用。另一方面，同时含有血红蛋白和可吸收氮源的处理导致蛋白酶活性和蛋白质降解的延迟增加，暗示了氮分解代谢物的抑制机制在起作用。此外，还对葡萄汁中的蛋白酶活性和表达进行了评估，结果表明表达和活性水平随着时间的推移而增加，这是有希望的结果，可用于进一步研究这种酵母对葡萄酒特性的影响。