Premium
Functional genomics of commercial baker's yeasts that have different abilities for sugar utilization and high‐sucrose tolerance under different sugar conditions
Author(s) -
TanakaTsuno Fumiko,
MizukamiMurata Satomi,
Murata Yoshinori,
Nakamura Toshihide,
Ando Akira,
Takagi Hiroshi,
Shima Jun
Publication year - 2007
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.1541
Subject(s) - biology , sugar , sucrose , genomics , food science , functional genomics , microbiology and biotechnology , yeast , genetics , gene , genome
In the modern baking industry, high‐sucrose‐tolerant (HS) and maltose‐utilizing (LS) yeast were developed using breeding techniques and are now used commercially. Sugar utilization and high‐sucrose tolerance differ significantly between HS and LS yeasts. We analysed the gene expression profiles of HS and LS yeasts under different sucrose conditions in order to determine their basic physiology. Two‐way hierarchical clustering was performed to obtain the overall patterns of gene expression. The clustering clearly showed that the gene expression patterns of LS yeast differed from those of HS yeast. Quality threshold clustering was used to identify the gene clusters containing upregulated genes (cluster 1) and downregulated genes (cluster 2) under high‐sucrose conditions. Clusters 1 and 2 contained numerous genes involved in carbon and nitrogen metabolism, respectively. The expression level of the genes involved in the metabolism of glycerol and trehalose, which are known to be osmoprotectants, in LS yeast was higher than that in HS yeast under sucrose concentrations of 5–40%. No clear correlation was found between the expression level of the genes involved in the biosynthesis of the osmoprotectants and the intracellular contents of the osmoprotectants. The present gene expression data were compared with data previously reported in a comprehensive analysis of a gene deletion strain collection. Welch's t ‐test for this comparison showed that the relative growth rates of the deletion strains whose deletion occurred in genes belonging to cluster 1 were significantly higher than the average growth rates of all deletion strains. Copyright © 2007 John Wiley & Sons, Ltd.