Ethyl carbamate control by genomic regulation of arginase inSaccharomyces cerevisiaeEC1118 in sugarcane juice fermentation

Abstract

Ethyl carbamate (EC) is one of the harmful byproducts which occurs in alcohol drinks, such as Wine, Rum, Whisky, Saki and other fruit wines as a result of a spontaneous reaction between ethanol and urea in the fermentation process. In this work, the relationship between arginase CAR1 gene in Saccharomyces cerevisiae EC1118 and EC generation in sugarcane juice fermentation was investigated. Results indicate that the content of EC can be controlled by regulating the expression of arginase CAR1 gene. Urea and arginase exhibited expression of arginase CAR1 gene, which resulted in an increase of EC content. Besides arginine and urea, the expression of arginase CAR1 gene was also significantly influenced by the content of ethanol, salt and culture temperature. Low fermentation temperature, (below 25°C) and lower ethanol and salt content showed some benefits in terms of controlling the EC content by decreasing the expression of arginase.

Occurrence of Ethyl Carbamate in Foods and Beverages: Review of the Formation Mechanisms, Advances in Analytical Methods, and Mitigation Strategies

“…Experimental genetically engineered and traditionally bred yeast. CRISPR-Cas9 and other genetic engineering techniques have been used to delete the gene CAR1 (which codes for arginase in S. cerevisiae) to prevent yeast from metabolizing arginine to urea (33,216). In pilot experiments with the low-arginase strain, EC formation in distilled spirits and wine was reduced by up to 70% compared with the controls (43,175,201).…”

The Screening and Isolation of Ethyl-Carbamate-Degrading Strains from Fermented Grains and Their Application in the Degradation of Ethyl Carbamate in Chinese Baijiu

“…However, the effect of elimination of the EC precursor, urea, on fermented food has not been discussed in detail. Deletion of CAR1 (coding arginase in S. cerevisiae) using CRISPR-Cas9 has been demonstrated to reduce EC concentrations by 70% [14][15][16][17]. However, in microorganisms, EC precursors are produced in various ways; hence, multiple genes have to be suppressed to reduce EC synthesis [18].…”