Vasyagin Egor A, Urakov Valery N, Shalamitskiy Maksim Yu, Cherviak Sofia N, Ivanova Elena V, Zagoruyko Valentina I, Beletsky Alexey V, Rakitin Andrey L, Mardanova Eugenia S, Kushnirov Vitaly V, Ravin Nikolai V, Mardanov Andrey V
Institute of Bioengineering, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia.
Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia.
Foods. 2024 Dec 27;14(1):54. doi: 10.3390/foods14010054.
In winemaking, malolactic fermentation (MLF), which converts L-malic acid to L-lactic acid, is often applied after the alcoholic fermentation stage to improve the sensory properties of the wine and its microbiological stability. MLF is usually performed by lactic acid bacteria, which, however, are sensitive to the conditions of alcoholic fermentation. Therefore, the development of wine yeast strains capable of both alcoholic fermentation and MLF is an important task. Using genome editing, we engineered a modified variant of the triploid wine yeast strain I-328, in which the arginase gene was replaced by the malate permease gene from and the malolactic enzyme gene from . Genome-wide transcriptional profiling confirmed the expression of the introduced genes and revealed a limited effect of the modification on global gene expression. Winemaking experiments show that genome editing did not affect fermentation activity and ethanol production, while use of the modified strain resulted in a tenfold reduction in malate content with simultaneous formation of lactate. The resulting wines had a softer and more harmonious taste compared to wine obtained using the parental strain. Inactivation of arginase, which forms urea and L-ornithine through the breakdown of arginine, also resulted in a twofold decrease in the content of urea and the carcinogenic ethyl carbamate in wine. Thus, the new strain with the replacement of the arginase gene with the MLF gene cassette is promising for use in winemaking.
在葡萄酒酿造过程中，苹果酸-乳酸发酵（MLF）可将L-苹果酸转化为L-乳酸，通常在酒精发酵阶段之后进行，以改善葡萄酒的感官特性及其微生物稳定性。MLF通常由乳酸菌进行，然而，乳酸菌对酒精发酵的条件敏感。因此，开发能够同时进行酒精发酵和MLF的葡萄酒酵母菌株是一项重要任务。我们利用基因组编辑技术改造了三倍体葡萄酒酵母菌株I-328的一个变体，其中精氨酸酶基因被来自[具体来源1]的苹果酸通透酶基因和来自[具体来源2]的苹果酸乳酸酶基因所取代。全基因组转录谱分析证实了导入基因的表达，并揭示了这种改造对全局基因表达的影响有限。葡萄酒酿造实验表明，基因组编辑不影响发酵活性和乙醇产量，而使用改造后的菌株可使苹果酸含量降低十倍，同时形成乳酸。与使用亲本菌株获得的葡萄酒相比，所得葡萄酒的口感更柔和、更协调。精氨酸酶通过分解精氨酸形成尿素和L-鸟氨酸，其失活还导致葡萄酒中尿素和致癌物质氨基甲酸乙酯的含量降低两倍。因此，用MLF基因盒取代精氨酸酶基因的新菌株在葡萄酒酿造中具有应用前景。
