Metabolic Engineering of Saccharomyces cerevisiae to Minimize the Production of Ethyl Carbamate in Wine
Metabolic Engineering of Saccharomyces cerevisiae to Minimize the Production of Ethyl Carbamate in Wine
复制标题
DOI：
10.5344/ajev.2006.57.2.113
复制
发表时间：
2006-06
影响因子：
1.9
通讯作者：
J. Coulon;J. I. Husnik;D. Inglis;G. V. D. Merwe;A. Lonvaud;D. Erasmus;H. J. J. Vuuren-H.-J.-J.-Vuuren-11958174
中科院分区：
文献类型：
--
作者：
J. Coulon;J. I. Husnik;D. Inglis;G. V. D. Merwe;A. Lonvaud;D. Erasmus;H. J. J. Vuuren-H.-J.-J.-Vuuren-11958174
酿酒酵母在葡萄酒发酵过程中将葡萄汁中的主要氨基酸精氨酸代谢为鸟氨酸和尿素。葡萄酒酵母菌株S.酿酒酵母在葡萄汁发酵过程中不能完全代谢尿素。尿素是由酵母细胞分泌的，它与葡萄酒中的乙醇自发反应形成氨基甲酸乙酯，这是一种对人类潜在的致癌物质。葡萄酒中酵母对尿素催化剂的缺乏可能归因于葡萄汁中存在的良好氮源对DUR 1，2基因的转录抑制。我们在S.酿酒酵母PGK 1启动子和终止子信号，并将该DUR 1，2表达盒（侧翼为ura 3序列）整合到工业葡萄酒酵母UC Davis 522的URA 3基因座中。体内试验表明，代谢工程的工业菌株减少了89.1%的霞多丽葡萄酒中的氨基甲酸乙酯。基因型、表型和转录组的分析显示，工程酵母522 EC-与亲本522菌株基本等同。
Saccharomyces cerevisiae metabolizes arginine, one of the major amino acids in grape musts, to ornithine and urea during wine fermentations. Wine yeast strains of S. cerevisiae do not fully metabolize urea during grape must fermentation. Urea is secreted by yeast cells and it reacts spontaneously with ethanol in wine to form ethyl carbamate, a potential carcinogenic agent for humans. The lack of urea catabolism by yeast in wine may be ascribed to the transcriptional repression of the DUR1,2 gene by good nitrogen sources present in the grape must. We expressed the DUR1,2 gene under control of the S. cerevisiae PGK1 promoter and terminator signals and integrated this DUR1,2 expression cassette, flanked by ura3 sequences, into the URA3 -locus of the industrial wine yeast UC Davis 522. In vivo assays showed that the metabolically engineered industrial strain reduced ethyl carbamate in Chardonnay wine by 89.1%. Analyses of the genotype, phenotype, and transcriptome revealed that the engineered yeast 522EC− is substantially equivalent to the parental 522 strain.