Classification, identification, and detection of beer spoiling microorganisms—A review

Mathias Hutzler, Forschungszentrum Weihenstephan - TU Muenchen, Freising, Germany
Co-author(s): Robert Riedl, Jennifer Koob, and Fritz Jacob, Forschungszentrum Weihenstephan, TU Muenchen, Freising, Germany

ABSTRACT: Beer spoiling microorganisms are categorized according to taxonomic, phylogenetic, physiological, and technological aspects. From a technological point of view they are categorized as obligate beer spoilers, potential beer spoilers, and indirect beer spoilers. Classification according to beer spoilage potential and occurrence depends on the selective, antimicrobial parameters of individual beer types. When considering many novel beer types with differing antimicrobial parameters, this classification becomes more difficult. This review summarizes the recent classification of and knowledge about beer spoiling microorganisms according to their taxonomic and technological characteristics. It should also include information about the novel beer spoiling species Lactobacillus paucivorans, Lactobacillus acetotolerans, Lactobacillus backi, Lactobacillus rossiae, Pectinatus haikarae, and Megasphaera paucivorans that have been described in recent years. Cultivation methods, molecular biological and chemotaxonomic identification, and detection methods for beer spoiling bacteria and yeasts are overviewed. Additionally a case study shows the current possibilities to detect, identify, and classify a beer spoiling microbe in modern brewing microbiology. In summary this study highlights recent knowledge about beer spoiling microorganisms and the different ways to cultivate, detect, and identify them.

Mathias Hutzler was born in 1978 in Regensburg, Germany. In 2004, graduated in food technology and food biotechnology, Technische Universitaet Muenchen- Weihenstephan, Germany. From 2004 to 2009, scientific assistant and doctoral degree at Chair for Brewing Technology, Technische Universitaet Muenchen-Weihenstephan. Since 2004, division manager microbiology at the Research Center Weihenstephan for Brewing and Food Quality, Technische Universitaet Muenchen-Weihenstephan. Main research fields include beer-spoiling bacteria and yeasts, molecular biological detection and identification methods, brewing yeast strain differentiation, hygienic monitoring, and biofilm characterization.