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Metabolic Engineering of Four GATA Factors to Reduce Urea and Ethyl Carbamate Formation in a Model Rice Wine System

Zhang, Peng, Li, Bang, Wen, Peng, Wang, Peilin, Yang, Yu, Chen, Qian, Chang, Yuxin, Hu, Xing
Journal of agricultural and food chemistry 2018 v.66 no.41 pp. 10881-10889
catabolite repression, ethyl carbamate, fermentation, gene overexpression, genes, metabolic engineering, models, mutants, nitrogen, rice wines, synergism, transcription (genetics), transcription factors, urea
Urea is the most important precursor of ethyl carbamate (EC), a harmful carcinogenic product, in fermented wines. In this study, the effects of four GATA transcriptional factors (Gln3p, Gat1p, Dal80p ,and Gzf3p) on extracellular urea and EC formation and transcriptional changes in urea degradation related genes (DUR1,2 and DUR3) were examined. Compared to the WT strain, the Δgzf3 mutant showed 18.7% urea reduction and exhibited synergistic effects with overexpressed Gln3p₁–₆₅₃ and Gat1p₁–₃₇₅ on extracellular urea reduction. Moreover, Δgzf3+Gln3p₁–₆₅₃ and Δgzf3+Gat1p₁–₃₇₅ showed significant 38.7% and 43.7% decreases in urea concentration and 41.7% and 48.5% decreases in EC concentration, respectively, in a model rice wine system. These results provide a promising way to reduce urea and EC formation during wine fermentation and raise some cues for the regulations of the four GATA transcriptional factors on the expression of individual nitrogen catabolite repression sensitive genes and their related metabolism pathway.