title: Improved ethyl caproate production of Chinese liquor yeast by overexpressing fatty acid synthesis genes with OPI1 deletion.
abstract: During yeast fermentation, ethyl esters play a key role in the development of the flavor profiles of Chinese liquor. Ethyl caproate, an ethyl ester eliciting apple-like flavor, is the characteristic flavor of strong aromatic liquor, which is the best selling liquor in China. In the traditional fermentation process, ethyl caproate is mainly produced at the later fermentation stage by aroma-producing yeast, bacteria, and mold in a mud pit instead of Saccharomyces cerevisiae at the expense of grains and fermentation time. To improve the production of ethyl caproate by Chinese liquor yeast (S. cerevisiae) with less food consumption and shorter fermentation time, we constructed three recombinant strains, namely, α5-ACC1ΔOPI1, α5-FAS1ΔOPI1, and α5-FAS2ΔOPI1 by overexpressing acetyl-CoA carboxylase (ACC1), fatty acid synthase 1 (FAS1), and fatty acid synthase 2 (FAS2) with OPI1 (an inositol/choline-mediated negative regulatory gene) deletion, respectively. In the liquid fermentation of corn hydrolysate, the contents of ethyl caproate produced by α5-ACC1ΔOPI1, α5-FAS1ΔOPI1, and α5-FAS2ΔOPI1 increased by 0.40-, 1.75-, and 0.31-fold, correspondingly, compared with the initial strain α5. The contents of other fatty acid ethyl esters (FAEEs) (C8:0, C10:0, C12:0) also increased. In comparison, the content of FAEEs produced by α5-FAS1ΔOPI1 significantly improved. Meanwhile, the contents of acetyl-CoA and ethyl acetate were enhanced by α5-FAS1ΔOPI1. Overall, this study offers a promising platform for the development of pure yeast culture fermentation of Chinese strong aromatic liquor without the use of a mud pit.
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China. yfchen@tust.edu.cn.|College of Bioengineering, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economic and Technological Development Area, Tianjin, 300457, People's Republic of China. yfchen@tust.edu.cn.
authors.forename: Yefu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Luo
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Gong
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Xingxiang
authors.initials: X
authors.lastname: Xue
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Guan
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Lulu
authors.initials: L
authors.lastname: Song
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Xuewu
authors.initials: X
authors.lastname: Guo
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
authors.forename: Dongguang
authors.initials: D
authors.lastname: Xiao
mesh_terms: D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism; D000103:Acetyl-CoA Carboxylase / Q000235:genetics; D000434:Alcoholic Beverages; D002208:Caproates / Q000378:metabolism*; D002681:China; D064429:Fatty Acid Synthases / Q000235:genetics; D005285:Fermentation; D005421:Flavoring Agents / Q000378:metabolism*; D017353:Gene Deletion; D012097:Repressor Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*
chemical_list: D000085:Acetates; D002208:Caproates; D005421:Flavoring Agents; C096105:OPI1 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000105:Acetyl Coenzyme A; C007650:ethyl acetate; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase; C079237:ethyl hexanoate
keywords: ACC1; Ethyl caproate; FAS1; FAS2; OPI1; Saccharomyces cerevisiae; Strong aromatic Chinese liquor