title: Effects of SNF1 on Maltose Metabolism and Leavening Ability of Baker's Yeast in Lean Dough.
abstract: Maltose metabolism of baker's yeast (Saccharomyces cerevisiae) in lean dough is negatively influenced by glucose repression, thereby delaying the dough fermentation. To improve maltose metabolism and leavening ability, it is necessary to alleviate glucose repression. The Snf1 protein kinase is well known to be essential for the response to glucose repression and required for transcription of glucose-repressed genes including the maltose-utilization genes (MAL). In this study, the SNF1 overexpression and deletion industrial baker's yeast strains were constructed and characterized in terms of maltose utilization, growth and fermentation characteristics, mRNA levels of MAL genes (MAL62 encoding the maltase and MAL61 encoding the maltose permease) and maltase and maltose permease activities. Our results suggest that overexpression of SNF1 was effective to glucose derepression for enhancing MAL expression levels and enzymes (maltase and maltose permease) activities. These enhancements could result in an 18% increase in maltose metabolism of industrial baker's yeast in LSMLD medium (the low sugar model liquid dough fermentation medium) containing glucose and maltose and a 15% increase in leavening ability in lean dough. These findings provide a valuable insight of breeding industrial baker's yeast for rapid fermentation.
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin Univ. of Science and Technology, Tianjin, 300457, P. R. China.
authors.forename: Cui-Ying
authors.initials: CY
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin Univ. of Science and Technology, Tianjin, 300457, P. R. China.
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Bai
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin Univ. of Science and Technology, Tianjin, 300457, P. R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Lin
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin Univ. of Science and Technology, Tianjin, 300457, P. R. China.
authors.forename: Xiao-Er
authors.initials: XE
authors.lastname: Liu
authors.affiliation: Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin Univ. of Science and Technology, Tianjin, 300457, P. R. China.
authors.forename: Dong-Guang
authors.initials: DG
authors.lastname: Xiao
mesh_terms: D001939:Bread; D005285:Fermentation; D005511:Food Handling; D005516:Food Microbiology; D005800:Genes, Fungal; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008320:Maltose / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D027981:Symporters / Q000235:genetics / Q000378:metabolism; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism
chemical_list: D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D027981:Symporters; C067575:maltose transport system, S cerevisiae; D008320:Maltose; C021534:maltose permease; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; C582346:MAL62 protein, S cerevisiae; D000520:alpha-Glucosidases; D005947:Glucose
keywords: SNF1; baker's yeast; glucose repression; leavening ability; maltose metabolism