Enhanced leavening properties of baker's yeast overexpressing MAL62 with deletion of MIG1 in lean dough.
This study aimed to increase maltose fermentation in industrial baker's yeast to increase its leavening properties. To this end, we overexpressed MAL62 encoding alpha-glucosidase (maltase) and deleted MIG1 encoding a transcriptional repressor that regulates MAL gene expression. Strain overexpressing MAL62 showed 46.3 % higher alpha-glucosidase activity and enhanced leaving activity than the parental strain when tested in glucose-maltose low sugar model liquid dough (LSMLD). Deleting MIG1 was much less effective, but it could further strengthen leavening properties in a strain overexpressing MAL62. The relationship between maltose permease and alpha-glucosidase was further dissected by transforming the two genes. The results indicated that without increasing the maltose permease activity, maltose metabolism could also be enhanced by the increased alpha-glucosidase activity. Previous strategies for strain improvement have targeted the enhancement of alpha-glucosidase and maltose permease activities in concert. Our results suggest that increasing alpha-glucosidase activity is sufficient to improve maltose fermentation in lean dough.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin, People's Republic of China.
Xi
X
Sun
Cuiying
C
Zhang
Jian
J
Dong
Mingyue
M
Wu
Yan
Y
Zhang
Dongguang
D
Xiao
D001709:Biotechnology; D050260:Carbohydrate Metabolism; D005285:Fermentation; D005433:Flour / Q000032:analysis / Q000382:microbiology*; D005524:Food Technology; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008320:Maltose / Q000378:metabolism* / Q000494:pharmacology; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000172:deficiency* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D000520:alpha-Glucosidases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*
C085976:MIG1 protein, S cerevisiae; D009004:Monosaccharide Transport Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D008320:Maltose; D013213:Starch; C021534:maltose permease; C582346:MAL62 protein, S cerevisiae; D000520:alpha-Glucosidases