CRISPR/Cas9-mediated Inactivation of arginase in a yeast strain isolated from Nuruk and its impact on the whole genome

Abstract

Despite the advantages of CRISPR/Cas9 technology in the food industry, controversy over its off-target effects exists. We engineered an industrial Saccharomyces cerevisiae strain isolated from a Korean rice wine starter, Nuruk, using CRISPR/Cas9 to decrease ethyl carbamate (EC) formation. We disrupted the CAR1 gene encoding arginase, which plays a key role in EC formation. Subsequently, we compared the whole genome of the engineered strain to that of the wild type by analyzing heterozygous and homozygous mutations through variant calling. Homozygous mutations in the genome of the engineered strains were identified as the target mutations in CAR1 induced by CRISPR/Cas9, and no other off-target effects were observed. Our findings have critical implications for the use of CRISRP/Cas9 technology in yeasts in the food industry.