Rapid Detection of Lactobacillus Brevis in Beer Production by the Combination of Microcolony and Fluorescence in Situ Hybridization (FISH)

Abstract

In this study, we developed an assay that combines a fluorescent staining microcolony procedure with fluorescence in situ hybridization for the rapid qualitative and quantitative detection and enumeration of spoilage bacteria in brewery process samples. Both quantitative and qualitative data can be gathered using fluorescent microscopy to visualize microcolonies labeled with a species-specific fluorescently labeled probe, and 6-darboxyfluorescein diacetate as a stain. Whereas traditional plating procedures can take up to 7 days, this assay shortens the processing time to 22 hr, while providing comparable rates of detection. The method was developed through testing on a known stock culture of Lactobacillus brevis and validated on brewery production samples. The results show that the method provides sound, rapid, qualitative, and quantitative results that can be applicable in a beer production facility.