Reduced production of diacetyl by overexpressing BDH2 gene and ILV5 gene in yeast of the lager brewers with one ILV2 allelic gene deleted.
Diacetyl causes an unwanted buttery off-flavor in lager beer. The production of diacetyl is reduced by modifying the metabolic pathway of yeast in the beer fermentation process. In this study, BDH2 and ILV5 genes, coding diacetyl reductase and acetohydroxy acid reductoisomerase, respectively, were expressed using a PGK1 promoter in Saccharomyces cerevisiae, which deleted one ILV2 allelic gene. Diacetyl contents and fermentation performances were examined and compared. Results showed that the diacetyl content in beer was remarkably reduced by 16.52% in QI2-KP (one ILV2 allelic gene deleted), 55.65% in QI2-B2Y (overexpressed BDH2 gene and one ILV2 allelic gene deleted), and 69.13% in QI2-I5Y (overexpressed ILV5 gene and one ILV2 allelic gene deleted) compared with the host strain S2. The fermentation ability of mutant strains was similar to that of S2. Results of the present study can lead to further advances in this technology and its broad application in scientific investigations and industrial beer production.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China.|Department of Life Science, Qilu Normal University, 250013, Jinan, People's Republic of China.
Ting-Ting
TT
Shi
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China.
Ping
P
Li
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China.
Shi-Jia
SJ
Chen
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China.
Ye-Fu
YF
Chen
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China. guoxuewu@tust.edu.cn.
Xue-Wu
XW
Guo
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, 300457, Tianjin, People's Republic of China. xdg@tust.edu.cn.
Dong-Guang
DG
Xiao
D000429:Alcohol Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D000483:Alleles; D001515:Beer / Q000032:analysis / Q000382:microbiology; D003931:Diacetyl / Q000378:metabolism*; D005285:Fermentation; D005516:Food Microbiology; D017353:Gene Deletion; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D000429:Alcohol Oxidoreductases; C470636:Ilv5 protein, S cerevisiae; D003931:Diacetyl
BDH2; Beer fermentation; Brewers’ yeast; Diacetyl; ILV2; ILV5