Zhang J, Zhang C, Qi Y, Dai L, Ma H, Guo X, Xiao D
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.
Genet Mol Res. 2014 Nov 27;13(4):9735-46. doi: 10.4238/2014.November.27.1.
Acetate ester, which are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction, are responsible for the fruity character of fermented alcoholic beverages such as Chinese yellow rice wine. Alcohol acetyltransferase (AATase) is currently believed to be the key enzyme responsible for the production of acetate ester. In order to determine the precise role of the ATF2 gene in acetate ester production, an ATF2 gene encoding a type of AATase was overexpressed and the ability of the mutant to form acetate esters (including ethyl acetate, isoamyl acetate, and isobutyl acetate) was investigated. The results showed that after 5 days of fermentation, the concentrations of ethyl acetate, isoamyl acetate, and isobutyl acetate in yellow rice wines fermented with EY2 (pUC-PIA2K) increased to 137.79 mg/L (an approximate 4.9-fold increase relative to the parent cell RY1), 26.68 mg/L, and 7.60 mg/L, respectively. This study confirms that the ATF2 gene plays an important role in the production of acetate ester production during Chinese yellow rice wine fermentation, thereby offering prospects for the development of yellow rice wine yeast starter strains with optimized ester-producing capabilities.
乙酸酯是由酵母细胞在酶催化的细胞内反应中发酵产生的，它赋予了发酵酒精饮料（如中国黄酒）水果香气。目前认为酒精乙酰转移酶（AATase）是负责乙酸酯生成的关键酶。为了确定ATF2基因在乙酸酯生成中的精确作用，一种编码AATase的ATF2基因被过表达，并研究了该突变体形成乙酸酯（包括乙酸乙酯、乙酸异戊酯和乙酸异丁酯）的能力。结果表明，发酵5天后，用EY2（pUC-PIA2K）发酵的黄酒中乙酸乙酯、乙酸异戊酯和乙酸异丁酯的浓度分别增加到137.79 mg/L（相对于亲本细胞RY1约增加4.9倍）、26.68 mg/L和7.60 mg/L。本研究证实，ATF2基因在中国黄酒发酵过程中乙酸酯生成中起重要作用，从而为开发具有优化产酯能力的黄酒酵母起始菌株提供了前景。
