Application of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) as a fast identification tool for beer spoilage bacteria

Beer spoilage induced by bacteria is a common problem in the brewing industry and has a great impact on the brewing economy. The present study aims to develop a quick, accurate and inexpensive method to detect and identify beer spoilage bacteria. To achieve this, an extensive database comprising about 6500 MALDI-TOF MS-profiles including more than 260 accurately identified contaminants and beer spoilage isolates was built. The 260 isolates represent all commonly encountered spoilage bacteria with a focus on lactobacilli, acetic acid bacteria and some anaerobes. The profiles revealed culture-independent species-specific biomarker peaks for all spoilage species, allowing straightforward identification of novel isolates. The final aim of the present study is to detect and identify spoilage bacteria in a sample with no or minimal culture steps