title: Effects of MIG1, TUP1 and SSN6 deletion on maltose metabolism and leavening ability of baker's yeast in lean dough.
abstract: BACKGROUND
  Glucose repression is a global regulatory system in baker's yeast. Maltose metabolism in baker's yeast strains is negatively influenced by glucose, thereby affecting metabolite productivity (leavening ability in lean dough). Even if the general repression system constituted by MIG1, TUP1 and SSN6 factors has already been reported, the functions of these three genes in maltose metabolism remain unclear. In this work, we explored the effects of MIG1 and/or TUP1 and/or SSN6 deletion on the alleviation of glucose-repression to promote maltose metabolism and leavening ability of baker's yeast.
  
  
  RESULTS
  Results strongly suggest that the deletion of MIG1 and/or TUP1 and/or SSN6 can exert various effects on glucose repression for maltose metabolism. The deletion of TUP1 was negative for glucose derepression to facilitate the maltose metabolism. By contrast, the deletion of MIG1 and/or SSN6, rather than other double-gene or triple-gene mutations could partly relieve glucose repression, thereby promoting maltose metabolism and the leavening ability of baker's yeast in lean dough.
  
  
  CONCLUSIONS
  The mutants of industrial baker's yeast with enhanced maltose metabolism and leavening ability in lean dough were developed by genetic engineering. These baker's yeast strains had excellent potential industrial applications.
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, Tianjin University of Science and Technology, Tianjin 300457, PR China. cyzhangcy@tust.edu.cn.
authors.forename: Cui-Ying
authors.initials: CY
authors.lastname: Zhang
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Bai
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Song
authors.forename: Dong-Guang
authors.initials: DG
authors.lastname: Xiao
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D003470:Culture Media; D005285:Fermentation; D005433:Flour / Q000382:microbiology*; D017353:Gene Deletion; D005800:Genes, Fungal; D008320:Maltose / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D013997:Time Factors; D014170:Transformation, Genetic
chemical_list: C065455:CYC8 protein, S cerevisiae; D003470:Culture Media; C085976:MIG1 protein, S cerevisiae; D009687:Nuclear Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C066502:TUP1 protein, S cerevisiae; D002245:Carbon Dioxide; D008320:Maltose