Acetate ester production by Chinese yellow rice wine yeast overexpressing the alcohol acetyltransferase-encoding gene ATF2

Abstract

ABSTRACT. 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.

Effects of Cynanchum bungei Decne Addition on the Physicochemical Properties and Antioxidant Activity of Rice Wine

“…Acetate is the main ester in rice wine, and it accounted for 86.55% and 82.80% of the ester contents of YW and CYW, respectively. The level of acetate depends on the concentration of its substrates and the activity of the yeast's own alcohol acetyltransferase [42]. The alcohols and acids in rice wine are another key factor determining the quality of rice wine.…”

Effects of Saccharomyces cerevisiae in association with Torulaspora delbrueckii on the aroma and amino acids in longan wines

“…The acetate esters were produced in much higher levels than ethyl ester; therefore, they impart significantly more influence over the flavor and fragrance (Saerens, Delvaux, Verstrepen, & Thevelein, 2010). The rate of acetate ester formation mainly depended on the concentration of alcohol and acetyl-CoA and the activity of the alcohol acetyltransferase (AAT) (Zhang et al, 2014). The synthesis of acetate esters, such as ethyl acetate and isoamyl acetate, in S. cerevisiae was ascribed to at least three acetyltransferase activities: AATase, ethanol acetyltransferase, and isoamyl AAT (Lilly, Lambrechts, & Pretorius, 2000).…”

Effects of the Mixed Fermentation of Torulaspora delbrueckii and Saccharomyces cerevisiae on the Non-Volatile and Volatile Compounds and the Antioxidant Activity in Golden Dried Longan Wine

“…Two major groups of esters are synthesized during fermentation by yeasts: acetate esters and ethyl esters [26]. Acetate esters are formed from an alcohol (complex alcohol derived from amino acid metabolism or ethanol) and an acetyl-CoA [28]. Most acetate esters (isoamyl acetate, ethyl acetate, isobutyl acetate, isoamyl propionate, and phenylethyl acetate) in golden dried longan wine cultures with a co-culture had a higher level than in the monocultures, similar results were observed by Zhang et al [7] and Arslan et al [25].…”

“…Among the acetate esters, isoamyl acetate (banana note) was detected in the largest amount by the co-culture in wines, in which the yeast was associated with an overexpression of IAH-encoded ester degrading enzyme and related with the branchedchain amino acid transferase gene BAT1, which is correlated with an enhanced production of isoamyl alcohol, which is the precursor of isoamyl acetate [29]. The concentration of alcohol and acetyl-CoA and the activity of the alcohol acetyltransferase (AAT) affect the formation of acetate esters [28]. These acetate esters are important as they are associated with desirable floral and fruity flavors in wine [27].…”