Detection of mannan from Saccharomyces cerevisiae by flow cytometry

Paul H. Chlup, James Conery, Graham G. Stewart

    Research output: Contribution to journalArticlepeer-review

    11 Citations (Scopus)


    Mannan plays an important role in the formation of some beer hazes. The effects of mechanical agitation of Saccharomyces cerevisiae brewing strains and subsequent impact on beer quality were investigated. Six different brewing yeast strains (ale and lager) were subjected to mechanical agitation in a temperature-controlled bioreactor. As a result of this study, a protocol is described for the determination of mannan residues from S. cerevisiae cells in nearly real time. Flow cytometric methods permitted the quantitative analysis of mannan residues based on particle size, relative granularity, and florescence intensity. The mannan concentrations and optical density of its supernatant increased as the yeast slurry was agitated. It was concluded that hydrodynamic stresses from agitation of yeast slurries cause mannan, an unfilterable haze constituent, to be released from the yeast cell wall. Furthermore, flow cytometry provides an innovative, rapid, and viable option for quantifying the influence that beer processing conditions have on beer stability. © 2007 American Society of Brewing Chemists, Inc.

    Original languageEnglish
    Pages (from-to)151-156
    Number of pages6
    JournalJournal of the American Society of Brewing Chemists
    Issue number3
    Publication statusPublished - 2007


    • Beer haze
    • Concanavalin A
    • Flow cytometry
    • Glycogen
    • Hydrodynamic stresses
    • Mannan
    • Yeast


    Dive into the research topics of 'Detection of mannan from Saccharomyces cerevisiae by flow cytometry'. Together they form a unique fingerprint.

    Cite this