Prediction of flocculation ability of brewing yeast inoculates by flow cytometry, proteome analysis, and mRNA profiling Article Conference Paper uri icon


MeSH Major

  • Cell Transformation, Viral
  • Oncogenes
  • Receptors, Cell Surface


  • The ability of brewing yeast to flocculate is an important feature for brewing of qualitatively good beer. Flocculation involves two main cell wall structures, which are the flocculation proteins (flocculins) and mannans, to which these flocculins bind. Unfortunately, in practice, the flocculation ability may get lost after several repitches. Flow cytometry was employed to analyze glucose and mannose structures of the cell surface by application of fluorescent lectins. Validation of the expression of the flocculin genes Lg-FLOl, FLO1, FLO5, and FLO9 was carried out using microarray techniques. SDS-PAGE, western blot, and ESI-MS/MS analyses served to isolate and determine yeast cell flocculins. Mannose and glucose labeling with fluorescent lectins allowed differentiating powdery and flocculent yeast cells under laboratory conditions. Using microarray techniques and proteomics, the four flocculation genes Lg-FLOl, FLO1, FLO5, FLO9, and the protein Lg-Flolp were identified as factors of major importance for flocculation. The expression of the genes was several times higher in flocculent yeast cells than in powdery ones. Flow cytometry is a fast and simple method to quantify the proportions of powdery and flocculent yeast cells in suspensions under defined cultivation conditions. However, differentiation under industrial conditions will require mRNA and protein expression profiling. © 2008 International Society for Advancement of Cytometry.

publication date

  • February 2009



  • Conference Paper


Digital Object Identifier (DOI)

  • 10.1002/cyto.a.20661

PubMed ID

  • 19072835

Additional Document Info

start page

  • 140

end page

  • 147


  • 75


  • 2