TY - JOUR

T1 - Prediction of flocculation ability of brewing yeast inoculates by flow cytometry, proteome analysis, and mRNA profiling

AU - Heine, Franziska

AU - Stahl, Frank

AU - Sträuber, Heike

AU - Wiacek, Claudia

AU - Benndorf, Dirk

AU - Repenning, Cornelia

AU - Schmidt, Frank

AU - Scheper, Thomas

AU - Von Bergen, Martin

AU - Harms, Hauke

AU - Müller, Susann

PY - 2008/12/12

Y1 - 2008/12/12

N2 - 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.

AB - 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.

KW - Flocculation

KW - Lg-flolp

KW - Microarray

KW - Microbial flow cytometry

KW - Proteome

KW - Saccharomyces cerevisiae

UR - http://www.scopus.com/inward/record.url?scp=60849100218&partnerID=8YFLogxK

U2 - 10.1002/cyto.a.20661

DO - 10.1002/cyto.a.20661

M3 - Article

C2 - 19072835

AN - SCOPUS:60849100218

VL - 75

SP - 140

EP - 147

JO - Cytometry Part A

JF - Cytometry Part A

SN - 1552-4922

IS - 2

ER -